Unfortunately, government welfare programs (social security/disability, medicaid, etc.) take months to process.
My office, and most of my colleagues, are happy to see folks who cannot pay in full, especially if it is medically necessary. I have it set up so a patient can make payments, even as small as $20 each month.
I encourage you to seek a good doctor and be upfront about his medical conditions as well as his financial condition. We appreciate honesty and will work with you.
Best of luck.