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.
I'm really bad at asking for help but if I had my time again I'd make sure your talks with managers are regular. If you are supposed to be working on a project make sure you ask which tests cover that area. You should ask to see the desktop of someone in your team how they work, how they navigate around the system and how they would add the functionality you're trying to do.
The documentation is garbage but that’s not so unusual. What’s unusual is that I have to ask questions in writing or schedule video calls with teammates if I want to learn anything that’s not in the documentation.
I know what onboarding is supposed to look like and this isn’t it. I’ve expressed these problems to my manager but I feel like I’m not being heard. Stress levels are through the roof.