I thought I was unmotivated and couldn't concentrate because I hated my job. I quit and found a new one with a 50% salary increase. I now make over $200k.

What I found after leaving is that it was a mistake. I miss my old job and I'm in over my head with my new job. The inability to concentrate only got worse, not better.

This problem is getting worse day to day. My effective work output keeps dropping until lately I'm getting about 1 hour of work done per day.

I'm falling behind and I can't keep up. 

I was seeing a therapist for a few years but he retired this year. He told me I need to get a psychiatric evaluation to figure out my concentration problems. Working with him he said that as a therapist he is capable of diagnosing me with PTSD but beyond that I need a psych eval. 

There's very few options in my area that take my insurance. Of the few options in my area, each has horrible, horrible reviews online. I can't find anything online that could take my insurance and diagnose me with what's wrong with me. Every online platform says diagnosis is off the table.

I cannot concentrate or get my work done. Physical symptoms of anxiety are increasing day to day. I think I'm getting close to the edge where I'll be fired or have to resign. My stomach is in knots most of the time and panic attacks are becoming more frequent and getting harder to prevent.

I've tried many medications for depression and anxiety but they never helped and several made things worse. 

What am I supposed to do to fix this? 

No attention/focusing strategy is working for me. I'm starting to feel "fight or flight" in my work, like I need to give this up and I need to leave, I'm in over my head, I can't do this, imposter syndrome, etc. and it defeats any strategy I try.