Desperately needing some advice..

Me and the father of my kids haven’t been doing good relationship wise. I tried to leave him both times before finding out I was pregnant. A part of me still loves him but I think it’s just because I’m used to us being together (going on 7 years). I’m only 23 so I know I have my whole life ahead of me. I catch myself feeling uncomfortable when I lay with him or when he tries kissing me, I don’t want to. Idk why I feel this way because like I said, I don’t really want to split up our family. Our current son is 16 months old and I’m pregnant with our second son due in June. I feel like I’d make a mistake if I left him but then again I feel unhappy most of the days I’m with him. He honestly is just an ass.. he’ll make jokes but they are mean jokes so I feel stupid for getting mad about them but I can’t help it. I tell him I don’t think they’re funny but then he’ll make a joke about that so I end up just ignoring him. I feel like I’m angry and tired all the time.. idk what to do.