C. -
This sounds like such a challenge - for you and for your son. I know that when my daughter is overtired, she has a more difficult time sleeping. I am sure with all the waking each night, he is very tired as are you.
I would love to know more about your son's schedule... when he wakes up in the morning, nap times, night time routine and finally "bedtime." Often, it can be that a tweak in the daily schedule can often help.
Is he in a crib still or is he in a toddler bed? Sometimes a crib is just not big enough for our growing kiddos, and they wake because they are a bit too confined in the crib. Just the same, if he is in a toddler bed, perhaps he wakes because there is so much room for him to roll around, etc.
I'd love some more information - and perhaps I have an idea or two for you. I am no expert, just a mom myself.
S.