In the US it's really easy to spend $1500 a month even on medicine alone, not to mention food, electricity, etc.
In other countries, $1500 is minimum wage, and in others it's maximum wage for most people.
Making $1500 a month in Belarus, for example, puts you in the top 1% of everybody.
Of course, that oversimplifies the problem somewhat, since any changes could worsen the situation overall, e.g. decreased mental health. Sitting in a bare room paid for by someone else and watching the wallpaper peel away has very little out of pocket cost, after all.
The counterargument is that homelessness and loss of medication would probably be far worse -- for example, it could be wiser to sell the car and live an ascetic lifestyle for 16-24 months until the disability appeals are processed, at which point the OP could return to an equilibrium. Stretching out the runway, so to speak.
Forming any actionable advice in this vein is impossible without a better understanding of the OP's costs, however.
In any case, selling his/her car seems like an easy way to cut costs.
However it sounds like medical costs are the culprit, which was the intention of my question.