Hi deadpoet. It sounds like you may have codependency issues. One typical definition is "having low self-esteem and looking for anything outside of ourselves to make us feel better, making the relationship more important to us than we are to ourselves."
I know how you feel; I've been there. I lived with a friend for many years and it was a toxic relationship. When she decided to move out I felt completely lost. I was willing to overlooked all the bad in order to maintain our relationship.
I was fortunate to join a group facilitated by a therapist that focused on codependent relationships. I'm now more confident in myself and don't look for my self worth in others. There are CoDA (Codependents Anonymous) groups out there that are either free or cost only what you can give be it $1 or more.