Stay or go?

My boyfriend and I have been together 4 years. We have a 2 year old son together. We fight constantly. It's so tiring. I don't even enjoy being home unless he is gone or I can focus on my son. We talked about breaking things off a week ago and though we are still living together we have had no relationship besides our son since. Except for last night. It was Friday and we were celebrating our son finally potty training and we went to dinner. I already knew what my boyfriend would get and how he liked it. And then thinking I know everything about him and how he is. It makes me feel safe. I know he still wants to be together but he said he won't change and all I have to do is just not argue with him and it would won't be a problem. Well easier said then done. He still wears our ring and everything. I am torn to stay or go. I have invested so much and we have a son. But I don't want to dread being at home if we are going to fight.