I have an extremely painful sinus infection. No money, no insurance. Otc meds don't work. How can I treat it at home and get relief?

Difficult question. Sinus infection is the result of blockage of the ostia (openings) of the air containing cavities in the face communicating with the nose. Therefore the treatment is ventilation and drainage. Or more specifically, the blockage has to be relieved. I can not believe that a community hospital emergency room could not help. If there is truly a sinus infection, you need good medical treatment.