I’m sorry you’re going through all that, I’m living in LA and also disabled from spinal issues so I’ve experienced a lot of what you’re talking about as well. I’ve basically resigned myself to ‘smoke weed all the time’ being the extent of medical management of my pain, because doctors can’t/won’t do anything else for me without potentially making other problems worse. Back problems are awful and not having any concrete answers is just about as bad.
What part of LA are you in, roughly, if you’re OK sharing? If you’re able to ride public transit I’d be happy to search around to try to find more resources near you.
In addition to getting arrested being dangerous, sleeping on a jail cot is probably going to be absolutely godawful for your back, at least as bad as sleeping in a doorway. If you’re sleeping on the ground outside you at least have some control over your environment, compared to jail.