Kylo,
I am sorry to hear what you are going through.

"It seems to me like BPD is almost a guarantee of MLC."
I can completely relate as my wife is diagnosed. I think that is one of the reasons I missed some things as I thought it was a symptom of BPD. However, after reading this site I'm not sure anymore.

"I called him and he left a message that he would be willing to see me..."
Not a good idea. My wife has seen various counselors throughout the years. She would often be more upset after seeing them. It's hard to tell what happened in the session as you are only getting her interpretation. Furthermore, many counselors may see it as a conflict of interest if they already had an established relationship.

I am a complete newbie, so I have no sound advice other than to suggest to you (as a BPD spouse for many years) a diagnosis does no good for you at this point.

I wish you well on your journey.