Hello, Lucky One... .I think it's certainly possible that your Depression is situational, and I also know that your wife's Graves Disease/Hyperactive Thyroid certainly exacerbates her BPD. I know this because my adult (37) son, who was diagnosed with BPD in early 2013, was also diagnosed with Graves Disease years before, and I can see how it made his BPD so much worse before treatment.
Is your wife being treated for the Hyperactive Thyroid? My son lost a dangerous amount of weight, became dangerously Depressed (became suicidal), and couldn't get out of bed in the morning to accomplish anything. Once the Graves Disease was treated, it really did help him physically, emotionally and mentally. I hope your wife is getting help for that... .
Have you had the chance to read any of the
links to the right-hand side of this page? I'd start with this:
Lessons for members who are staying in their relationships. Though you cannot control your wife or her BPD behaviors, you
can control how you communicate with her, and lots of us have found that once we stop pushing every one of our BPD loved one's buttons, things can get at least a little bit better.
Is your wife still in Therapy with a Psychologist and/or Psychiatrist? If so, please know that it takes more than just a few sessions for her to start seeing changes. My son has been in recovery since March 2013 (Out-Patient, Psychiatrist, DBT, and Neurofeedback Therapy since April 2013), and is still in his various treatments. I don't see him being able to stop them anytime soon, but I do see his progress and he is the happiest and healthiest he has been since he was a young boy. And the family is a lot happier as a result... .
Can you tell us a bit more about your situation? I'm so sorry that things are so tough right now, but I want to let you know that there is a lot of support and insights to be found on this site, and things really can get better