I'm with you, champ...

But I've found my health improves significantly with a few things, which hopefully might give you a few tools (this is just a random brain-fart, I hope it's helpful):

Personally, if I stop feeding on feeling trapped and wishing I was never born and instead start focusing on the little things I can do to influence today or tomorrow for the better, it generally unwinds this knot (and sometimes that's just tidying up a little! Put a favourite song on and let that be a timer, maybe).

Walks and outside are awesome, but if you can find some curiosity or awe, it's even better (waterfalls, pretty flowers at a botanic garden, watching anything narrated by Sir David Attenborough) - partly this is just to 'move your perspective away from oneself'.

Riding bikes always feels nice too - especially slowly and gently, that sensation of rolling along is lovely.

Sitting in a swing and ever so gently rocking back and forward - don't 'go for it', but keep it gentle and slight, it's a very different ride.

It took a long time to find socialising useful, I get tension headaches from it so it was hard, yet I could always see that we're social animals and remaining isolated was a path to disaster (personally). So I stuck with it. Now I've got a few groups of buddies I see roughly monthly which 'helps'. Sometimes I still get headaches and opening up is something I force myself to do, but it's becoming less of a hurdle and they seem to still appreciate me...

Helps hearing about others challenges, too -life's not easy and it's not just you suffering!

Slowly my map of the psychic pain is changing, but stopping from feeding it is only part if the first step - you've got to start building something new, too. All of this is slow and small steps, not manic or sudden changes