I know its hard to appreciate other people trying to give advice when your headspace is not there, but burnout is a very real thing. It sneaks up slowly when you keep thinking you can take on a little bit more, a little bit more and then all of a sudden it becomes overwhelming.

It's happened to me where I was having full panic attacks seemingly out of the blue and passing out on public transport.

The only advice I would say is to try to force yourself once a day to really step away from it for at least an hour, maybe two if you can, keep the time you do it regular so it becomes a habit and be okay with saying no.

Your mental health is way more important than any work. Hope things improve.