Why is my ex still so mean? After 9 months.?

After 9 months I would think my ex and I could at the least be able to construct and maintain a civil conversation. I will get this out the way, yes I still love the guy. However; I'm not in love with him. I can't just not love him we were a strong serious couple for almost 3 years until it ended. I broke it off due to him fighting a lot more. I had no choice but to move or have no place to live. We both are college students. I studied and lived in PR. I encountered some family issues and had no choice but to move back to NY. I would visit him after each trimester. He came to visit me once ( he's from NY as well). Anyway, its been 9 months. He accuses me of " abandoning" him, even tho he knows I had no choice. We woman tend to get soft after a brake up. Well now I'm over that. I've stopped asking if he still loves me and the what ifs and so not... Now I try to have a friendly convo with him. B4 new years I asked to start fresh and leave all drama in the past. I apologized if I did anything wrong. He was very sweet about it and said I had nothing to be sorry for and it would be ok to be friends. Now since the brake up I've been talking a lot more to his family and I been a lot more outgoing and successful. This is my problem: When my ex and I talk, we talk normal for about 10mins. Then somehow some way he brings up the relationship. He starts blaming me and looking to push my ons. When I stay calm cool and collective he just pushes harder! He says vulgar things and then says " if you were how you are now back than we would have still been together... Now ur like this when I have nothing to offer you" Why is it that after 9 months he's still so mean and vulgar and can't not talk about the relationship? He says he's over me and has moved on to other girls... So why is he like this? Always trying to make me feel some sort of gilt or make me feel bad ? This guy has made me go to hell and back for him. Why can't he just be blunt and honest? 9months later