What is the point

Why do I keep checking up on him on his accounts. He will lie anyway and wants to be with her so why do I keep thinking that things will change?! My mom is right...maybe we both need help since we are doing it to each other. I need to stop for my own piece of mind and to show I'm not "crazy" like they think I am and continue to talk about me. Why should I care...it hurts but most of all we are still on the same house so it's hard to try to get along even for the kids sake.