i could never stay in a relationship that didnt consist of trust and loyalty. ugh i absolutely hate that feeling in the stomach you get from all the mixed emotions that swirl around when it comes to dishonesty,resentment,anger and love.change is hard.nobody wants to be with a cheater but the relationship is routine and sometimes people would rather stay in a miserable relationship rather than make a big change. people become "comfortable" even in an undesirable environment. he is not holding you back from happiness-you are!  stop self sabatoging yourself and get rid of this jerk! u have been with him a long time! dont waste another second!!good luck!!