What should i do about our relationship?

i am engaged to my boyfriend of almost two years. when we first started dating he was a student at widener university with a high gpa. he lived on campus and came home every chance he could to be with me and my daughter(from a past relationship). we now live together and have our own daughter. he also has a son from a girl he had a one night stand with who is only four months older than my daughter. he is no longer going to widener, but he is an online student. he cant keep a job. he calls me names, puts down everything i do, brings up stuff from my last relationship, plays video games All night long while im sleeping. and sleeps all day. its two days before christmas and i feel like i could leave him and give up on our family at this point. oh and he is only 20 and im 21. everything was perfect in the beginning. i had a job and was a full time student. granite i lived at home with my dad, i still did everything i could to take care of my daughter and me. what do you people think i should do??