Hi S.. I have not had to deal with this yet, but I also have a 4 month old with colic so I have done a TON of research on sleep.
I would try swaddling your little guy again - it might make him sleep longer.
Each time he gets up, let him fuss a little bit longer, and after a few nights, some of those awakenings might merge into one if you keep buying time.
Also, have the baby's father try and soothe him. If you go and try to do it - he'll expect milk. This might also buy more time.
He might just be trying to soothe, so you can also try feeding him for less and less amounts of time, and then putting in a pacifier or your pinky for him to suck on.
Lastly - is he getting fed every 3 hours during the day? The more calories he gets during the day, the less he will need at night.
The book - No Cry Sleep Solution has some great tips on weaning babies off of nursing through the night.
Good luck! I am sleep deprived too and it stinks!