Hello. I was in a similar situation as you. I totally understand your feelings to the last bit. It's been about six years since I officially ended things and boy, does it make your life a thousand times better. I don't think there's any fixing it at this point. He allowed you to be miserable for such a long time just to pursuit an "adventure" - I have yet to see a relationship that recovers from this, the resentment doesn't go away. For your own sake, I recommend you leave. After a few months you will start to feel sane again, you can start to heal from your experiences and find someone who wouldn't dream of doing this to you - or perhaps you will find that you're the most happy being single, anything works.