I suggest leaving him. I've been in a similar situation and the guy cheated on me TWICE, and I forgave him for both times, thinking it was just a slip up and he really loves me. Eventually though, he broke it off with me and replaced me with another girl, and despite the times he cheated on me and treated me like crap, I still cried. It's normal. I cried for days. I gave myself time to grieve. I always thought I was alone and HE was my only pillar but after losing him, I started seeing the people around me who has always been helping me without me noticing.
After that, things started getting better for me; more opportunities, more freedom, just literally more for me. It may seem bad now, but once you give yourself time to cope, I'm sure you'll do just fine. I wish you luck! (: