Social Security benefits for children are one of the most difficult cases to prove -- the child obviously can't work so the medical evidence has to determine that the child cannot function normally based upon the illmess. Having a complete medical evidence of record and supportiove information from the child's doctors and schools are very, very important.
There is no cost to file for Social Security benefits -- simply call your local SSA office and set up an appointment. They do have onluine application's available, but you may be better off going in person or consulting an attorney first. If you do not have the funds to send your son to a doctor, Social Security can send him to a doctor to be evaluated and they will pay for that evaluation -- be warned though that most Social Security evaluations are that the person is not disabled.
Public assistance and social security benefits are totally different -- we do provide our clients with a list of social service organizations in our area to help them through the waiting period. There are an amazing amount of services and organizations who will assist people -- with day care costs; medical care; counseling; support etc.
One of the first things I would suggest is go to a social security attorney to talk to them about your sons disability and see if it meets the criteria. The second thing I woudl suggest is call an organization like Catholic Charities or Lutheran and Children Family Services to find out what kind of help there is available in your area.
Some drug companies have free prescription services for individuals --- there is a lot of help if you just start looking. Good luck.
If in doubt apply for Social Security for the child with or without an attorney, you don't need an attorney to do that. You do not know the outcome till you try. However be sure to provide all and I mean all medical evidence and supply the records yourself if possible as well as statements from relatives, teachers, and anyone else that might be even vaguely useful. if you get denied then definitely get an attorney. While child cases are unpredictable many attorneys will take the case. Also, there are social security advocates, non attorneys, who also handle these sort of cases.