Hah - the first time you said "Hot Tube." I was thinking, don't know what that is but I want one...
A good chair makes all the difference. I hope you can fit one into the budget soon. Maybe check Craigslist and Freecycle for used ones? I got lucky and nabbed a Harman Miller chair at the dump.
Hope you feel better soon.
I hope I might find a deal on something this year lol, I put things off sometimes 💤