Shame/ guilt

Feel very strong feelings of guilt and shame towards ex( poa). Basically I used him for sex. It lasted 2 mnth. First time I met him I really missed his friendship,, but I wasn't strong enough and really seduced poor lad. We not in commitment to anybody. Tho I was committed to myself to get better and stay strong. All 5 mnth I couldn't move one with my physical feelings. It's was obsessing fantazy. Few days back I just started to ignoring him and said I need space . Tho he d give me that for 1 day max. Attention drives me nuts! And if he was nice I'd just be opposite. So today it's first day I haven't spoke with friend?. I feel very ashamed that. Couldn't refuse my sexual desire, fantasies and went for it! And then I kept going hot/ cold for 2 mnth... I wasted his time. Tho I said it's no way we going back together. So he studied with me helped me to do theraphy ( john Bradshaw inner child). But I think it's wrng!!!amab is in denial!! Big time. And that acceptence of whatever ll need he will do drive me even further away from him. So I want to stop using him, his time , his help because I feel such a terrible person. I pry for forgiveness , life seems empty without this drama going on. But it's not healthy, I now deep down. I felt so great before meeting him. And today it's just fantasy gone. Have no disire to sleep or pretend that we can befriends. It's sucks! I'd love to have friend but I d always get intimate thoughts in my head and it's wrong.. Has anyone understands me? Because I don't.