Hello MMarie
While these boards are geared toward Borderlines, a lot of the lessons that are learned here can be applied to all relationships.
Building self-confidence can be hard. It can be even harder when in a relationship with a disordered person. But, hard does not mean impossible!
One thing that might help is establishing and enforcing boundaries. This will curtail negative treatment of you, and that will help to provide a place for self-confidence to grow. There is a good article on boundaries here:
Setting Boundaries and Setting LimitsSelf-confidence can also be gained by trying new things and taking pride in your accomplishments. Are there any new things that you've been wanting to try but haven't for whatever reason?