You can apply for SSI by calling the main number (I can look it up for you if you want).
I applied all on the phone and they send you forms to explain your condition, sign and send back. It really is simple. They do all of the leg work getting your medical records and such. They will probably send you for an evaluation (of your claimed condition) to their doc. When I applied it took 60 days to go through.

Let me know if I can help you in any way.