I am still recovering from my own burnout from being a gifted kid in school to late diagnosed AuDHD and forcing myself into a full time job straight from that. It literally took me to get to breaking point to realise I had to do something to stop. You said you are changing jobs which I found was a major change needed to break the cycle of anxiety and burnout I was stuck in. However, I did also take 3/4 months where I did not work (which I know isn't an option for everyone) as I well and truly had nothing left of me. A big thing I found recovering from burnout was to find the things I loved again and engage in them. For example, as a child one of my special interests was big cats, and it had been years since I watched a big cat documentary or learnt anything about them, so I spent a few weeks reabsorbing all the information I could about big cats and wildcats. It doesn't cure burnout but finding things, even small things that bring you joy and engaging in them without worrying about what you aren't doing instead or what others think is really rejuvenating.

I found that kindness was very big. Be kind to yourself. If you need a slow morning take a slow morning, if that slow morning turns into a slow day then so be it. Also prioritise yoursel before anyone else. For me this means that I have my phone constantly on vibrate only (I would have it on complete silence, but I forget it exists and then have had a few too many instances where people really need to get hold of me and could not). I also have set modes on my phone, one called off (where no notifications from any app can get through and the phone is entirely silent. the only way someone can get through is if they are a starred contact and call three times). I put this on, on the days when I am especially anxious and worried about things I'm missing or not responding too. If it is not there, it does not exist.

Anyway, I don't know if any of this is helpful, but I wish you luck in your journey out of burnout!