Through all the pain, hurt and wreckage...I found something wonderful, Me.
I believe people and events come into our lives for a reason and to learn about ourselves, not them. I learned much of my help of others, gave me a sense of being needed and self worth. My "happiness" was depended on others. I allowed others to define who I was. I needed to be needed, it gave me a purpose. My ego was running the show. Helping others allowed a distraction from focusing on me. None of these things were done on a conscious level either. I simply was not aware of the reasons and the whys because I never took time to ask those questions or learn about me.
Madison, he is who is he is....addict, bipolar, BPD, or whatever. It's shouldn't be your concern any more. Finding YOU in the wreckage, is what really matters. Only you can answer the what and whys of what you were getting out of it and what you have learned about you. I hope you put the time focusing on you!
I suspect you knew he was the lucky one to have you. He was not in your league....and you wanted to help him reach his potential. Now ask why you sought out that kind of relationship.
As humans are motives are usually not as "pure" as we want to believe. IMO