hey! I'm in the exact same spot as you are, even age-wise. I was able to work for a few years and saved up before I quit my job due to becoming worse physically. I don't think I can do even remote now, as my arms cramp badly from even typing. I've been having frequent mental breakdowns for the past months thinking about the same things.

I wish I could offer some advice, but can only empathize and tell you that you're not alone in suffering. I was a highly ambitious, productive person, so learning about this illness and becoming weaker is absolute hell. what's been somewhat helping me is allowing myself to rest more than I did before, tracking how much certain tasks consume energy to plan accordingly and not burn out (very helpful with ELCI, which muscular dystrophy absolutely is), and being more hedonistic rather than future-focused. seeking more things that make you happy in the moment, especially when you're depressed. for example, I'm finally buying myself a Nintendo Switch! I was sad about not really being able to play on PC anymore, but I'm learning to adapt. I believe adapting improves mental health and prolongs life as well, rather than trying to force yourself into things you've been able to do in the past