I know how devastating this is to you.
But the solution to all lies in you. Its not just one persons responsibility to hold on a relation over years. You should make him realize that once you marry, the entire thread of hope lies in trust and loyalty.
He has broken it and gone behind your back. Your husband is just keeping you just to save his face and he doesn’t wants to be insulted in front of everyone.
You say you knew the mistakes what you have done but living with only builds the guilt inside you. Confront him, give him a ultimatum,either you or her. The only reason he is continuously doing so is that he believes you are weak. Stand up and question against him.
You can lead your own life.
Just take a leap of faith.
What will happen will happen and what needs to be done will be done.
Wish you nothing but good luck.
your friend veentherapy.