I too struggle with this, though in a different way than you I suppose. I don't fall in love easily, but when I do it's very much like hypomania (I suppose falling in love is pretty similar to hypomania for "normal" people too). However, afterwards I find it hard to commit and build on a stable, loving relationship. I'm inclined to doubt and criticize my partner (mostly internally, since I know it to be unfair).

I too am drawn to people with their own issues, without consciously seeking them out. All women I had serious relationships with had some formal diagnosis at some point, and quite a few of the not-serious as well. I know I would probably be happier with someone without issues, but I don't seem to be interested in them.

My advice would be to try and take things slowly. Don't promise too much, make clear that you want to take it slow, but at the same time make sure that you are serious in your intentions. Allow your feelings to come and go without attaching too much importance and actions to them. Allow for time and initiatives on your own. Practice mindfulness if it helps you.

Good luck!