Going for ADHD diagnosis

I'm looking at booking an assessment for a diagnosis but I'm conflicted.. i keep rotating through thoughts of, 'yes let's get assessed, something is there' to 'nope, all in your head, don't bother wasting your money'. Has this happened to anyone?

I'm 33 now and also diagnosed with BPD, Bipolar II and C-PTSD.

I relate to soo many quirks that I've seen others have and they relate it to their adhd so I wonder, but then when I start to be proactive at booking an assessment, the voice in my head says, nope, it's probably just the mixture of diagnosis' that i already have.

I'm in Aus, so the assessments aren't exactly cheap. I'm not sure what I'm worried about - perhaps being judged?

It'd be handy to know if anyone relates at all