Confused and broken

I met my husband when I was in high school. He was the first lasting relationship I had. He was always cold, but I hoped that he would "grow to love me". I know that was not healthy thinking, but I've had an alcoholic father all my life and have never really had good examples of how women should be treated. I let him get away with everything always being about him. He literally never helped me with the most simple or important life tasks or decisions. I've been hurt or felt alone in so many little and big ways. He just doesn't get it. We seperated when he went to stay with his family overseas on a half year vacation to "rest from a stressful job", and to see if he'd like to stay there forever. I did not agree because I wanted to work on our marriage. He left anyway. I then saw him for who he really was and told him I'm done. I wanted to be someone's pride and joy, and I sure didn't feel that way. Now a year has passed since he's been back and I cannot get myself to file for divorce. He's been in my life for over ten years. I feel like he's a huge part of my life and heart, although we never shared anything including finances and life's joys and sorrows. When he left I met an amazing guy. He embodies every quality I want in a partner. Caring, loving, helpful. Something I never had. We have an amazing bond and relationship (although I'm not divorced) but I don't talk to my X. Why can't I then make myself file for divorce? The husband doesn't know about my "boyfriend" and when we do talk he constantly tells me he's changed, understood, or grew up. (he's 38). I don't believe that he really did from our conversations. Why do I then feel like I owe my husband something (although only he benefitted from our marriage)? Let me add that according to my faith I don't even have a marriage because it was a civil union. I need to "decide" what to do with my life, but somehow I cannot let go... And I also don't want to lose the best man and friend I ever met. I also did go to therapy btw and the doctors always say I did not have a relationship.

What in the world should I think about all this this?