Hello everyone!

So I've been having some issues with my man and I want you to tell me what you think. Hes cheated on me twice now but I feel that I am too forgiving. We are great most of the time other than this. Recently hes been unhappy but he never opens up to me. How am I supposed to know that I'm doing something wrong if he doesnt tell me and keeps me in the dark? He also talks about me and the problems he has with me to other people but not to me? Again, how am I supposed to fix it if I dont know about it? I love him and he says he loves me. He makes it seem like everything is genuine but it seems like hes sugarcoating his feelings. He wont call it off and I will not either. Weve been together for 3 years. What do I do?