What am I to do with this situation?

I'm a 31-year-old single parent of a 3-year-old, pre-schooler with severe Autism. I am at the end of my rope. I have no friends, hardly any family support, no child support from my child's father. His father has only seen my son 3 times, and has not called in over 10 days now. I can't work because my son has the opportunity to go to a special education center preschool from the age of 3 to 5 years, that the state pays for. That is the only opportunity he will have with getting any kind of therapy for his autism at the moment. I have covered all of the bases, with getting his name on a waiting list with the Regional Office for some funding to cover expenses like equipment and respite care, and additional therapies. And the governor of our state just signed a law where the insurance companies have to cover all autism services, therapies, medications, etc. I am depressed, lonely, isolated, drained, burned out. Never getting a break from my child, but only 3 hours he is gone to preschool. All day long, it's chaotic, with temper tantrums from having sensory integration disorders, not eating his food, not playing with his toys properly, and constantly having to be rocked ALL THE TIME! I love him to death, the institution isn't an option. I can't work anywhere for 3 hours. I want my son to get early intervention. I"m all he has. I don't know who I am anymore. My hopes is that when he goes to school all day, that I can find suitable work during those hours. At the time being, there are no daycares that can handle autistic kids in the area, no after school care, and ABA therapy is 90 bucks an hour, until the new law pes next year. WE live off of 650 bucks a month, that's what he gets for SSI, and our rent is 450 a month. What am I to do?