Get a lawyer specializing in these things.

It is difficult and painful to obtain SSI and then have issues that come up where they ask you to pay back every cent and then needing to fight that and prove this or that without a lawyer. An advocate is essential. SSI exists to help people, unfortunately they can assume the role of enemy at times in their efforts to purge people from the rolls who really don't need or can do without.

They certainly won't believe you have a need if for any reason they believe your son can work, ha - not without a lawyer! :)

Getting social security to understand your situation is impossible without the support of a good SSI lawyer. A good SSI lawyer normally does not charge you unless you are able to obtain SSI. SSI then gives you a number of backpayments to the day that you applied and the lawyer takes a cut of those funds. A good SSI lawyer also helps make sure you are understanding all of the details to manage your funds properly so you don't lose SSI. They can also set up what is called a special needs trust where you can keep funds that do not count as a resource under SSI guidelines. You need to apply with a lawyer's assistance. Even if you didn't have an issue with qualifying, an SSI lawyer to help you from the start is super beneficial in every way!