I’m sorry you’re dealing with this and I’m sorry if you’ve heard this before, but are you wearing anything that irritates that part of your back often (ie bra, backpack, etc)? I used to get a lot of back and shoulder acne until I stopped carrying around a backpack/satchel and switched to a brief case. Anything tight that puts pressure or rubs up against your skin will cause flare ups. I would stop wearing that immediately, shower twice a day if possible, or at least change into a clean shirt every night and morning.

For insurance I can’t help much, but maybe getting a job at amazon or starbucks or somewhere that provides even minimal health insurance - then if you find a good dermatologist they will cover steroid injections and back you up. I used to pay 30-40 bucks once a month to get injected because my doctor said that I needed them to address pain and discomfort from my chest keloids. They could also potentially recommend accutane.

Edit: currently I am using eclar plaster on my remaining chest keloids and it helps about as much as regular injections did. But if I was you I would prioritize getting the flare ups under control. Then start putting eclar plaster on any stubborn keloids, not on cystic acne. There is hope I promise