On this forum, you belong wherever you feel comfortable.
I've got an appointment on July 9th too!! But it's a phone one because the psychologist won't be in tis town for July or August.
BPD and Bipolar have a fair amount in common and they often get misdiagnosed as each other. If you've been seeing this psychologist for all 3 years, then I would try (hahahahah right, gotta love that one) to not worry about it too much because she probably knows you pretty well by now and only wants the very best for you.
Read through the threads in the BPD forum, you might find that you have a lot in common with people there! And keep on posting in here too, it's all about comfort.