Sorry to be the bottom-line voice of reason, but this is painful to witness otherwise, so you need to hear this:
TRUST and RESPECT are the absolute cornerstones of a good relationship. When these are compromised, and you accept it, you are putting yourself in a pathetic position. This is what has occurred in your relationship. Stay - and you are destined for HELL. Leave - and you have a chance to start over with your self-respect intact.