Mom/Son get SSI

My son is 10 years old and gets SSI because of his ADHD/ODD. I get SSI because I have spina bifida and depression. Recently, I was diagnosed ADHD/PTSD as well. Together, we get about $1200 a month and I have approximately $700 in bills (NOT including gas or food which is another $300). My ENTIRE SSI amount goes to bills and if you're wondering, yes I am on housing and SNAP. My SNAP, however, is a mere $25. I keep being told that my son's SSI is for him and ONLY him, so if all my SSI goes to bills I guess that means I can't eat? I can't go with my son into a movie because I would use his SSI to buy my ticket? He and I are a unit, a single entity until he is old enough to begin work, or turns 18 (which ever is first) and seeing as how he's only 10, he is unable to do certain things by himself and even things he can do by himself, I still have to participate in a supervisory capacity. We can't stay home all day. With ADHD, if we're not doing something until bedtime, we get severely depressed and start picking at each other. I do as much as I can with him that's free, however, being in a wheelchair severely limits what I can do with him. I'm trying to get off SSI through a vocational rehab program, but with as bad as my PTSD/ADHD is, I don't think that I'll be able to maintain a job full time for very long. I just don't know what to do at this point. Thank you.