To stay or not to stay

I’ve been on and off with my current well not boyfriend at the moment. I’m 23 and he’s 26. It’s been almost 5years: We are trying to work things out but whenever he gets mad he gets drunk & verbally abusive towards me and his mother. which is (Everyday) and he texts other girls just out of spite, Which is the root of why we fight and don’t work out this relationship. He lied about going to the “gym” I followed him and saw he was having dinner with a Co-worker, I also found out that he NEVER told his supposedly girl bestfriend (which I didn’t care that he had one) but whenever she would ask him about me he would DENY me these past 4years, He said he’ll never forgive me for ruining his relationship with her. I’m hurt especially by the fact that he’s trying to turn into what I always wanted him to be, he finally admitted to being an Alcoholic and is trying to get help, but I’m just know sure this is what I want anymore. Im Exhausted. I’m just at a loss for words and I’m trying but I know I’m not trying as hard as I could be. I’m not sure if I really care or just feel sorry. Someone new came into my life and I want to give him a chance, I don’t want to leave someone I love for someone I like but this someone I love isn’t treating me as I should be. My feelings are everywhere right now.