Have you tried any therapy? If so how has that worked for you? Also it was great for me to just talk to my parents about it. I know this is not possible for everyone but it did great things for me. Talking on here might also help I hope.
On a scale of 1-10 how would you say you rate your self esteem? Part of my destructive relationship seeking behavior was tied to my low self esteem or more importantly that my self esteem was almost 100% tied to the person I was currently dating. So I would think my self esteem was sky high at times cause I had the girl I wanted. But I was really just using her to fill myself with self esteem that was really not there if the pretty girl was not on my arm.
Sadly it was a long process to feel that I am an amazing person without a beautiful girl validating that opinion. This really just took a lot of time and personal growth. To me self knowledge helped the most in this area. If your on this forum there is a good chance you are willing to look deep into yourself and find ways of really improving yourself and the way you interact with people. Not many people do that and this alone puts you have many other people who literally would fall in "love" with the next person to bat their eye lashes in their general direction. I have been there and it sounds like you may have too, but being able to turn around and face that problem is a huge first step and it sounds like you are here doing that. So give yourself a lot of credit for that.
Other than that I sadly don't have a magical line that I think can do the trick. I would do a lot of self examination. Think what you really want in life and how your action with this women will most likely drive you further from that. Think how bad things in the future will be if you simple continue to take the same actions and are unable to learn from your experiences. Think of how few people really know themselves, and how that can help you find where you truly can connect with people on your terms in a way that you love. Hopefully this will help you turn what once felt like love in the past into a part of yourself you can start to understand and eventually control. This can even make you stronger and help you recognize this same part in others. To either avoid it for your safety, or to point it out to them for their safety.
Hope this Helps, Again ask any questions,
Kurt