Why I can't leave?

I have a boyfriend, who has been with me for the last eight years. I can't seem to leave him. He doesn't love me as I supposed, and we are different, but we are tied together. We have a lot in common, and he is my only friend now (others have left or moved away with the war). I am afraid of being alone because every time I left him, it was very painful. I don't love him as a man anymore, and building a family with him was a foolish idea. But I love him as a friend, and we have a big history together. We both have mental issues and anger problems, I have BPD, and he has BD.

I have no support and no one to help me leave him (now, I spent my attempts and failed). He is not a bad person, but he will never marry me (he said he would only if necessary, but I want a man who sees me as his partner and wants a child). We have both changed a lot, and he says he liked the old version of me more. I think, that girl was foolish; she made many mistakes and kept returning to him after trying to leave.

Also, I never looked at someone else before, but several months ago I met someone special. He went to the war two months ago, so not in my city. I think he likes me also, but we don't speak in messengers without reason, because it would be not fair since I am in a relationship.
My current bf appeared when I did this in the past (speaking with a new man being in a relationship), and things went just wrong after this. I want everything to go correctly now, my current bf should not love me or find someone (I did this before, found a girl and matched her with my ex, and it worked brilliantly).
I want things to go well for both of us because before when I left him with problems, I always returned. I have some sort of dependence.

It was very hard, these 8 years were a challenge for me. I left before too soon and wanted to work on relationships, but it's a dead end. When I left him before I was in such pain that I couldn't work and returned back when the money ended. I think money is a kind of issue, but the main problem is that I can't tear him off my heart. I was ok before when he said no marriage, we maybe won't have children, we should pay equally (when he doesn't do housework equally) and other things, but now it seems he just wants to live comfortably no matter what I think.