J.V.
I hate to say this, but maybe your son just doesn't need the sleep?
My brother NEVER slept. He still doesn't to this day.
As a baby, if he slept 7 hours, my mom was thankful. His norm was 5 1/2-6. He didn't nap either, maybe 15 minutes here or there, but there was just too much work to do to be bothered with shut eye. ;-)
Hang in there. I'm sure you are barely making it. Lack of sleep is as rough as it gets! Good luck!