SERIOUS QUESTION: are there some cases where someone w bpd/bpd traits doesn’t improve with therapy or meds?

I’ll be having my first official dbt session tomorrow & this therapist hasn’t diagnosed me yet but 2 other specialists in the past yr said I show symptoms of bpd. I’m honestly kinda cynical, tried talk therapy with a few therapists maybe 5+ yrs ago & they didn’t help me at all. Tried a few meds & that didn’t make a difference, I manage my emotions a lot better now but still not fully where I want to be. When I explained this to my mom & these recent potential bpd diagnoses, she said it’s my decision if I want to do anything about it. All my life I’ve been told there’s nothing wrong with me & that makes me 2nd guess my mental health, as something always felt off but maybe overthinking it. I don’t have the patience to keep looking for the right counselor or trying meds again since I’m a lot better now, if this new counselor ain’t it I’ll probably just stop seeking support & will manage on my own as I have.