feeling conflicted

Okay I have this boyfriend and we have had some bad ups and downs the first 5 months of our relationship he was cheating on me having sex and sexting another girl but I didn't break up with him idk why then after a year he started hitting me and that went on for s full year and I started to fight back I hit him after he stoped because I couldn't stop idk why then I've now been with him for 3 years but i don't feel that strong for him anymore and he is a sweet guy he is nice looking had a good sweet side good in the bedroom and stuf but there is this other guy and we just understand each other with my boyfriend now he would never let me vent and now he is trying f hit this other guy has always been here for me and I just really like him help?