How common is misdiagnosis and how does one deal with it?

I don’t know how to feel or what to do moving forward. I’m hoping there’s someone that can relate to my situation or shed me some light.

Basically I’ve spent the last few years highly suspecting I’m AuDHD. It perfectly explains my experience and struggles growing up. I’m currently pursuing a clinical doctorate after switching from a career of 10 years in the performing arts due to burnout, but this is now the hardest thing I’ve ever had to do in my life and it’s highlighted my functional struggles now more than ever.

My psychologist at uni suggested I see a psychiatrist (first time I’d see one) to possibly get medication for my inability to concentrate and executive dysfunction (possible ADHD), insane difficulty socializing and social/general anxiety plus depression. However, after mentioning all of this to the psychiatrist, she dismissed it all because I told her I did well in school growing up, and since I didn’t have struggles with my graces nor see a psychologist when younger, I didn’t have ADHD nor Autism, and if I had characteristics, I most probably overcame them. She said I just had bad anxiety.

It made my struggles and experience feel so unvalidated. I literally suffer so much from as long as I can remember, and it gets worse with age. I was hoping it would finally be the start of my journey to getting a diagnosis and start addressing my neurodivergence, but now I feel gaslit and I’m doubting myself completely. I know it’s super common for a misdiagnosis, especially for women and the ADHD + Autism combo, so I wanted to know if there was anyone else who’s gone through this? There are barely any specialists where I live that treat neurodivergent adults, there is so much misinformation or just no knowledge at all from health professionals regarding this, and the very little options I have for official diagnosis I can’t afford, at least not right now.

What the hell is one supposed to do? It’s INSANE we just have to live like this, in a system that doesn’t favor us at all.