Hey there, sorry to hear about what you are going through. I was diagnosed with ADHD at a young age, it has gone untreated but that's another story. In my adult life I've dealt with anxiety and depression. I've recently been diagnosed with bipolar.
My daughter (20ish) had a very similar outlook as you. She was confident she had ADHD and wanted a diagnosis. But similar to you her psychiatrist wanted to focus on anxiety and depression. She pushed back against this and didn't make progress.
But recently she went through a severe depressive phase and sought help. Instead of seeking help to get a specific diagnosis she went in simply asking for help.
You could try going to a psychologist and saying I'm feeling x, y, and z and they are impacting my life in a, b, and c ways. Then let the expert guide you through what you need.
I'm not saying this is you, but my daughter was convinced she needed to be treated for ADHD. But she really needed to be treated for her depression first.
Separate from all that a word of caution from someone who is prescribed a controlled substance. If you come in strong asking for an ADHD diagnosis you might be flagged for drug seeking behavior. It's better to present what you are feeling and let the docs try and figure out what works.
Best of luck to you, life isn't fun when it feels like your brain is out of control.