This is why I truly love support-driven development.
While it’s possible to prioritize problems that don’t affect most people (squeaky wheels) it’s a hell of a lot more effective than most of the methods I know to have a very low barrier to contacting you for users, and fixing the things that come up.
GetCalFresh.org. Way easier way to apply for food stamps. Felt good to have left after 6 years going from helping 1 person get help to over a million. Still going strong.
Also lots of strangler pattern iterations! That was fun.
I'm really sorry you're dealing with this. I'm going to mostly share info about public benefits in case it's helpful, just because that's what I know (and I don't have as much knowledge about some of your other questions.)
What state are you in? I know you mentioned SSDI, but just to relieve some of the stress of getting by, you should try to apply for as many public benefits as you might be eligible for (SNAP/food assistance, Medicaid [medical care], affordable connectivity program [internet], Lifeline [phone.]) With little or no income, you should get some decent support from these programs.
For getting disability support (SSDI, or SSI), you might consider getting a lawyer. You're right it can take a long time to get this, but odds go up if you have a lawyer helping you. You can also contact your local legal aid which you may qualify for based on income.
In terms of jobs I'll do some thinking and see if I can post more. Are there any activities that you can definitely do without getting stuck due to your disability? There are definitely options for flexible computer work, and also things that are more phone-oriented.