My wife has what look like borderline traits, though probably not full BPD. She has the spurts of rage, the emptiness, the projective identification (i.e. "I'm angry so I'm going to manipulate you into getting angry enough that I look reasonable", the sabotaging behavior. Trouble is my limited understanding of the disorder combined with filtering it out from her other mental problems. She has been diagnosed with OCD and GAD. The OCD is the usual germ fear, but also "toxic" chemicals and the fear of having run people over with a car without noticing. The GAD in particular is probably what they are now calling "somatic symptom disorder," (SSD) but that term didn't exist at the time and her doctor was older. I say SSD because the worry is almost exclusively related things she feels that she is afraid are signs of illness or life-threatening injury, e.g. pain in the lower back is terminal kidney failure. She is no longer under any doctor's care.
Why I have trouble is her anxiety-based disorders generally involve seeking my reassurance in a compulsive manner. If I fail to provide the reassurance in a way she likes or point out that the reassurance-seeking is mental-health based in any way and not a completely reasonable thing to ask, I awaken the beast. I have family with all manner of anxiety disorders and they don't do anything like that. Sorry if I seem like I'm rambling. I've just been spinning so bad these past few months and not really found a solution.

Selkie3
Only a professional can sort out what is what when there are mixed issues going on, and even then it may take a while to get to the bottom of it.
It is quite common to have several disorders compounding (called comorbid).
Have a read of some of our lessons
communication and validation. These will help you with reassuring anxiety based issues, and avoiding having to agree to things you don't necessarily agree with.
Even without a specific diagnosis many of the lessons learned here will help with interacting with people who suffer emotion sensitivity. It is better to learn how we can change the way we interact, for the better than stressing too much over diagnosis. Many people never are diagnosed, and never even admit they have a problem.
Keep reading and asking questions, this a great place to help you through this maze, and you are not alone
Waverider