Help me out should I dump this guy or what?

I have been in a relationship with this guy for four years. I have helped him through school joining a fraternity and have totally supported him when he has struggled. Now I am 7 months pregnant with his first child and He has flipped the script (change his attitude towards me). He talks down to me, talks about my child, makes negative comments about me. He doesn't support me at all at least I don't feel it. He continues to think he can do what he wants and say what he wants and its' okay. I feel that he is either scared of the responsibility, having second thoughts about this baby or is looking for a way out. Or he just has issues. So tell me what you think.