Great job on nursing your baby!
Here's a lifesaver for you: keep her in bed with you overnight, and use the side-lying nursing position. Perfectly safe if you do it right (learn details at askdrsears.com or get the Dr. Sears Baby Book or Nighttime Parenting Book). And you pretty much sleep through every feeding.
So easy, so wonderful, so much safer than a crib (if you ask me).
It also means, of course, that you can sleep while she nurses during the day! Just make sure that, if you bring your 3-year old to bed with the two of you, that you are between both girls.
Really, it's marvelous. Just takes a tiny bit of getting used to the new position. Use "top" breast or "bottom," whatever is most comfortable, and support your baby with a pillow at her back. You might prefer a pillow for your own support, as well. A baby blanket under her is great for catching leaks, spit-up, etc., and with the pillow there for her, you don't have to remember which side you fed her on last - you see where the pillow is, and switch.
For more breastfeeding support and fantastically helpful information, go to the La Leche League International website, llli.org.
Keep up the marvelous mothering! Things are just about to click into place for you. I do remember that much - everything gets easier right about at the 1-2-month mark. And when I started side-lying nursing, my world went right-side up again. It's the easiest thing in the world; you sleep as much as you need to, day or night. In fact, you start to look *forward* to feedings, because they mean you get to sleep, if you need to!
L.
PS don't give up and switch to formula because you think it might be easier. It isn't. You might think, well, at least my husband or other caregivers can take a load off by doing feedings and I can take a break. But there is plenty else for them to do. You get the easy job: rest and feed your baby while getting to sleep or, while awake, gazing at her lovely little face. Everyone else can do the dishes, take out the trash, fold laundry, feed the pet, clean up clutter, take care of your 3-year old, cook...see what I mean? :) :) :)