Does your county or state help out with low income people? Many do and you may not be aware of these services - they often dont advertise much?
Its impossible for anyone to figure out what you have really. Maybe you have some sort of infection? Or fibromyalgia (widespread muscle and joint pain, sometime frequent urination) or something entirely different?
Somehow you're going to have to see a doctor. Public hospitals cannot, so far as I understand, refuse someone if they are ill. Consider that if something is really wrong then you're greatly increasing your ultimate financial costs by allowing it to get worse by not seeing a doctor.
You might want to check out the symptom checker on Health Central (upper left hand side) to see if it can give you a clue but it sounds like you really need to see a doctor.
http://www.healthcentral.com/
Good luck!