Struggling to Get a Diagnosis for BPD/EUPD

i feel i've been hassling my gp and basically any medical professional that i've seen in the last few months for a diagnosis of BPD/EUPD and i am so tired of having to fight for it. i've been in and out of therapy since i was 14/15, taking absolutely everything that they've offered me, and i am far from better. i was referred for a second time now a few months ago for a psychological assessment - still nothing. how long am i supposed to wait to get some answers? i have good days and bad days, and god knows i've grown a hell of a lot on my own, but on days like today it feels like such an insane uphill battle just to be alive and i don't want to be alone in this anymore.