My wife is diagnosed BPD.  It took her a long time to get a proper diagnosis as she was diagnosed with bipolar for years. Her mother is also BPD.

For me, the hardest part of being married to a borderline is how every fight we have(and there are many) is centered around my mistakes, never hers(because she doesn't have any in her version of reality.) And then her reality snaps back and she cries and says "I'm sorry."

As our marriage continued the praise I received was slowly and methodically replaced with criticism. I don't know if this is a BPD thing but my wife plays the victim to an extreme extent.  Everything bad that happens in her life is never the result of her choices but always the result of someone else victimizing her.

So yeah, the hardest part of being married to a borderline is being force-fed negativity on a daily basis.  But I love her like nothing else.  Maybe that makes me codependent, I don't know. 

   