Really need to talk to someone about dating a married man and putting up with him going back to wife

I need too vent about the man I'm in a relationship with. I seem to only attack married men. This man that I'm having difficulty with is my Co worker actually my team driver . He's the prefect Co driver so when he hit on me 3 years ago I was floored he's not at all handsome but a great heart. Well I agree to be **** buddies but no didn't want that it was be with him or nothing. Well he hooked up against every fiber of my soul well being alone for 5 years ok I done it. He leaves his wife and we are together until I make him mad and he goes back to wife and I put up with this ****. So this is the second time he's gone back and actually waiting in him now . What the hell is wrong with me?