How do you regain a sense of self?

A Buddhist would probably say something like "well played sir" (referring to the process of the "game of life" as a kind of illusion). To see through the illusion is the most important part. What you do after is not so important. You have already passed a threshold from which you are hard pressed to return. Attempting to return causes the experience of desire and suffering. It's going with the revelation and flowing forward along the path of least resistance... that is the way!

I think that if I were to have a mantra like that for me personally... I would begin with "I don't know myself". 

I like to feel strong. I work out at the gym to feel strong. It's easy to present a strong front. You know what was hard for me? Being weak in front of my partner. Being weak and depressed and going to talk to my pastor about it with as much honesty as I could muster. I had to tell my doctor that I was feeling suicidal. I scared the man because he doesn't hear that a lot. People don't like to advertise their weakness. I believe, the weakest and most cowardly lie people tell each other nearly every day is "I'm fine"... Tell me what strength means to you? You have blood, bones, skin, hair, a whole body that holds together. You are naturally strong in this way. You do not have to do anything special to hold together. No person, apart from yourself, gives you this power. It comes from you, and you alone, without effort.

I am ashamed in so many ways. There is probably a special thread somewhere about it. This is as good a place as any to explore those feelings. I think that many people, that look on but rarely speak, could benefit from your courage to talk about your personal feelings of shame. 

I feel inadequate sometimes because I could not persuade, or cajole, or fix, or convince, by any means, to have my POA stay in relationship with me. Not even as friends (if that were somehow magically possible, but it's not). I spent the last 20 years learning about how to relate to people and I picked apart POA's psyche to the best of my ability in order to find some magical, graceful way to overcome what is an impossible problem. POA has free will to do with as she pleases. So do I. I am free to seek out people that will value me, be in relationship, reciprocate love, spend time with me... 

A person is free to continue a path in pursuit of illusion and desire as well. You have that strength of will inside of you naturally. If I scolded you and told you to stop... you would fight me with a lot of your strength! You are stronger than you realize.

I'm not talking about putting up a front. I have no problem being emotionally vulnerable. That is all I have been and I have gone too far that way. I have no self. That's what I mean by strength. Motivation. A vision for my life. A reason to let go of him where he is not the one in control but I am. I don't mind being angry at him as that helps me get over him. It's what I usually do with POAs and it always works. I just find it difficult this time around because I don't see where I have power. I like those youtube videos where people say "if he doesn't want tou he isn't worth your time". That's what i mean by strength. I don't want to waste my life being sad over an not a very nice person. I guess I want the right to call him an not a very nice person.

I was vulnerable too. I was sincere in my intentions towards POA. I wanted to marry her. All I got for showing my heart was a series of stabs to my most vulnerable places. I chose to show them and I received a consequence.

Not everyone does this. Some people do. It's very cruel and it's a reflection of her inner state as someone who feels cruel towards men on a daily basis. Now, in my situation POA was determined to destroy our relationship and so was I at some points. We mutually and systematically worked towards hurting one another. 

If I understand your situation, your POA has not overtly rejected you as a person or a gender or... I don't know. He just has no reciprocated your desire to be in a closer relationship. I've said it before and it made you mad. You are not entitled to any kind of relationship with anyone. Relationship is something that must be given mutually and freely.
I was not sure if the first sentence here belonged with the previous thoughts. If you want an external source of motivation, join the army. A drill sergeant will run you until you puke your guts out and then run you some more. He will motivate you... You do not have to desire this motivation. It is imposed upon you or you are insubordinate and face discipline. 

The military specializes in breaking down an individual's ego and putting it back together in a way which is useful to the government. Interestingly enough, many people find the change empowering, but after the fact. Nobody likes to be forced to change against their will or even against their apathy.

I think that you like your freedom. With that freedom comes a natural responsibility as an adult. I think you don't give yourself enough credit. You have a job, you feed yourself, clothe yourself, you have a roof over your head, you travel to and from your work, you have friends that you talk with... You have some things going for you that you may not be acknowledging. 
The real question is, why are you angry? Are you angry that he did not reciprocate? Flip the genders on that for a second. If a guy was mad at a woman for not reciprocating his affections... 

I'm also not sure where the power differential comes in here. Why do you need power over him or yourself? What does "power" mean here?
You could privately call him anything and personally feel any way (good or bad) about it. Your inner life of attraction, anger, shame, sadness, or even strength will probably not change his lack of engagement or alter his interest level. It sounds like he has made himself clear and you are in the process of accepting this fact.

One model goes something like this, Denial, Anger, Bargaining, Depression, Acceptance. Where would you say you are in that list? Sometimes when I consider it, I'm all over the place, angry one day, depressed the next. When I feel my version of strength, I am in acceptance. When I am looking back fondly at the illusion of POA, I'm in denial. 

Yes it's very true. I talk about gender all the time. I've taken lots of classes on gender psychology and I've read a lot of books about feminism (1st, 2nd, and 3rd wave). Gender is an important distinction. I think it is safe to say that laws surrounding persistent unwanted or unwelcome contact in the workplace (specifically boss to subordinate) apply equally to men and women independently of a political or social opinion.
I think the one thing that is clear is that I am having a little difficulty tracking with you. Please correct me as needed. I sincerely do not want to misunderstand. I don't know your specific working condition but, in the states, workplace fraternization is pretty much frowned upon. Work environments differ, but... I'm thinking that it is safe to say that the workplace is not an environment to be seeking intimate relationships. If we look at the definition of an addiction, usually it involves some kind of escalation. I'm not sure what your specific workplace has in place as far as policy goes.
I'm wondering what you are trying to control? Are you trying to control your own feelings? Are you trying to control him by getting his attention or reciprocation? If strength for you means motivation and power means strength and control... I'm confused. It feels like a circular thought. Strong = Control = Motivation = Power ?

But I do see what you mean about a general lack of clarity between the two of you. Maybe there was one moment where he was figuring it out and he finally arrived at a firm decision about how to interact with you in order to keep himself safe. You got strung along for a moment or two before he decided. That does not mean he owes you some apology or explanation... You know for certain now. You can be sure.

I mean, in my situation, I knew for sure over a decade ago and yet, here I am still messed up and thinking about POA. I know just how hard it is to say goodbye to the potential you saw in a possible relationship. That is an illusion. But you had already figured that out...

See that's what I mean about power. These 2 quotes:

He is not a suitable person with whom to have a romance


He does not determine my worth.

These 2 give me a sense of power. I think because it give a me a feeling of acceptance and of rejecting him also.

Thanks very much!

My only reservation about these "Mantra" are that they revolve around "him"....
LovelyJune challenged me once to stop thinking about the things POA "does" or the "effect" POA has on me, and instead focus on myself.
If I were to adjust these "Mantra" accordingly...

“I own/possess myself”
“The world does not owe me attention/affection”
“there are better and different environments in which to pursue a romance”
“I determine my worth”
“I am OK”