I self-diagnosed myself with "BPD tendencies" months a year before I was officially diagnosed with it. I was posting on here when I was dealing with emotional stuff. I dismissed the idea that I could have BPD after I was diagnosed with a bi polar disorder, because I thought that you couldn't have both and be able to function as well as I do. I also sometimes question my BPD diagnosis because I am high functioning and a Pdoc once said that he didn't think I have it. However, I trust the word of my long-term therapist over a Pdoc I have seen once. Also, my BPD friend used to say "I can see a little borderline in you" and I have had other Ts drop hints to me that I have it.
I find that this forum is the most helpful forum for me. Since my Bi polar illness is a "mild" (it sure doesn't feel mild lol) one, I benefit more from having people help me out with my emotional reactive and low self worth stuff. As long as I don't abuse alcohol too much, I can manage my bi polar stuff unmedicated and with little assistance from others. This forum also helps me with my anxiety more than the anxiety forums because I have been struggling long enough with anxiety that I need more thought-centered advice (if that makes sense).
It is YOUR health and you have the freedom to post where ever you feel that you will get the most benefit. We're here to help. Good luck