Really confused about this situation.

I know this guy for more than two years. At the beginning he was in a reletioonship and we were just friends. I was single and I did my own buisness.
One year ago, while he was still engaged, it happened something and we slept together. After a week he broke up with his girlfriend and it started a fwb relationship between us. At one point I realised that i was feeling something more about him, so I told him. He told me that he likes me a lot and he spends great time with me but he didn't want anything serious. I accepted this. In fact I knew for sure that he was still sleeping sometimes with his ex girlfriend and also other people. I couldn't be angry for this with him, in fact i didn't. I tried only to explain that i wanted something more and if he didn't we had to end it.

He said "I care about you, maybe things can change, I don't know, I don't know what i want." I said "I can understand you, but if you care about me and don't want anything, do it for me and let me go". Everytime we ended it, he always came back with beautiful words and I, stupid I know, fell into him again.
In all this year I never dated someone else or did anyting with anyone. I refused everybody, respecting my feelings for him. I have always been faithful, even if he repeated to me that I had to do my stuff because that's what he was doing. I gave everything to him, I was kind and careful, i always tried to make clear that he was important to me, I stuck my neck out because i felt to be like that. I justified all of his behaviours, when he didn't answer texts, when he lied or avoid the problem, when he disappeared for long time and then came back as if nothing has happened, when he was with someone else. I was stucked in this and I forgot my dignity because I hoped everytime he came back, things could be different, but no, he didn't change his mind. And everytime he came back, I felt used only for sex and that hurted me a lot.

So, 3 weeks ago, i said to him once for all "This is over. If you want me, tell me, If you don't, let me go." He didn't say anything in these weeks so I convinced myself to stop it.
Last weekend I were at a party and there was him too. I was really drunk, at one point he came to me, I couldn't say no and we had sex. After that I was confused, I felt hurt again and i felt stupid and miserable for falling again. The same night, another guy approached me, I had sex with him too. I know I have done something awful, and I feel horrible about this. I didn't do it for revenge or something like that, maybe I did it because I thought that this would have helped me to get out of this situation. The effect was opposite, I felt guilty and like I cheated. The first thing I did was calling him and telling "I slept with someone else after you". He didn't say anything except "the important is that you did after me and not before". The next day i contacted him and told him that i felt awful about what I did, I felt guilty because I love him and I realised this even more after that. That I lied to myself, I believed that I could turn page because he didn't want me, but no, I couldn't. I told him that i realised that i can't do my stuff if we don't end it once far all, even if I should because he always said that he don't want anything serious from me. I apologied to him. He treated me bad, he told me that i am a s**t and all the feelings that i confess to him in all this time were a lie.

Now I feel that it's all my fault and I can't forgive me. I think that if there was one possibility, I ruined it with this single episode. I really don't know what to do.
Does he have the right to believe that, after this episode, all my feelings are lies and treat me like this? Because I tend to justify him once again, and I can't understand if this is only my problem to solve with myself, or if I actually did something bad to him. I am not proud, to me, of what I did, of course, but if he always said to me he didn't want something more, what's the point of being so bad to me now?