Hey, it's me a couple months ago! With a side dose of "we may or may not fire you, we dunno yet" for several weeks (they did, abruptly, the day after once again saying they maybe wouldn't, and I guess I'll never know exactly why). Confusing as hell and unlike anything I'd experienced in my not-short career. I guess some managers/teams are straight-up incompetent at onboarding and blind to how hostile-to-new-hires their codebase(s) and docs are. Oh and useless, god-awful justify-your-existence-to-your-manager (then tune out because nothing anyone else says matters) standups every day adding to the stress. And no planning process to speak of. It's the second time in my life I've felt actually-mentally-ill and the other involved a sick newborn, so. That's impressive for them to have achieved, I guess.
Save money if you can and look for cheap/free credit lines, is my advice. If you can get a few months' worth of bills in the bank or available on super-cheap credit then the worst-case (shit, best-case, for me—I felt so much better after) scenario won't really be that bad. Hit up your network if you can and see if anyone needs some contract work, if things don't work out. It's pretty easy to scare up a few hours here and there, maybe enough to at least cover bills.