With our first I felt guilty about going to sleep when Amy had to stay awake. That meant that there were two sleepy, inefficient people zombying around trying to deal with routine stuff.

With the second, I firmly slept through anything I couldn't deal with, and was (relatively) alert and ready for things I could deal with.

So don't feel guilty. Sleep is important for you too. If you can't sleep and there's nothing you can do about it*, then go somewhere else -- put a sleeping bag in the basement or something -- and get yourself some sleep.

*Although of course adding moral support is sometimes something you can do that's useful, or essential, so if staying awake does that then go for it. But otherwise, sleep, guilt-free.