My son never had colic, thankfully, as that might have pushed me over the edge. :) He, however, never slept through the night until 14 or so months.
The one thing that did help was a visit with LLL, and a lactation consultant. I learned about cluster feeding, and that seemed to help some with the longer sleeps. (Like you, I didn't do the formula thing to fill him up- gets in the way of the supply issue!). And, I learned from LLL the true art of nursing while in bed- no light. That helped a lot, since I could lie down, and the light wouldn't wake anyone up more. I wonder if you can set up a mattress on the floor in the nursery, temporarily, to allow for co-sleeping? It might help.
The best news is that this IS temporary. And, when you find yourself becoming overwhelmed, remember that you are not spending the next 6 months like this...it is just 'one more night'.
