Ex Boyfriend issues: what to do?

My bf is my ex bc he was talking to a woman online who just wanted sex and he was "telling her what she wanted to hear"... the second incident was he was actually talking to a diff girl on his cell while I was picking up for dinner and afterwards while using my computer. I think he has issues with boundaries and comprehending things and knowing when to take pple serious. He has epilepsy so I've watched him before and got him his meds several times when he's had partials and fullblown to keep him from hitting his head on stuff, etc.... I didn't know a whole lot about it and told him if he didn't start seizing I was gonna call 911. I talked to his mom and she said that's typical but if he seized non stop for a certain amount at a time, then call an ambulance. If you say F U; he'll say what where how hard and even now he'll do it. He's jealous or something at the idea that I might be with someone else. And says nasty things like no one would want me for diff reasons: being heavy set and not satisfying in the bedroom although I assure u I did satisfy him.

What do I do or should I change my views. I try not to let it bother me. But it's low what he says sometimes; I can probly block him on here but part of me feels obligated to be a friend, I will not make the mistake of being his gf again. There are other things that not sure are appropriate to mention, etc. If anyone wants to discuss other stuff PM me; feel free.... advice would be helpful. Thanks

You're letting this guy win. You need to stand up for him, tell him that if he doesn't treat you better then you're going to stop talking to him (sounds childish but you know what I mean). Don't let him win. I know what you mean about feeling obliged to be friendly but he sounds awful! You'd be much better without him!
Amy