Well, sweetie, I feel for you, but I can't really say that I blame your daughter! Have you ever tasted formula? It tastes like vomit, especially when you compare it to how sweet breastmilk is.
What have you done to try & increase your supply? It's possible that your daughter is just going through a growth spurt & that's why she's eating more right now. Also, it's VERY common for caregivers to overfeed breastfed babies. Every time they cry they offer them a bottle & b/c babies love to suck, they'll drink it down, even if they're not hungry.
There are LOTS of things that you can do to increase your supply and your pumping output.
Here are a few examples:
TAKE FENUGREEK: 3 pills, 3x/day. When your pee & sweat start to smell like maple syrup, you're taking enough
EAT OATMEAL: oatmeal or granola (with whole oats in it)
PUMP WHILE YOU'RE NURSING: You can get a Made for Mom's pumping band to help make it less akward OR you can get a really cheap, snug fitting sports bra & cut a slit on each side that's just barely big enough to put your pump flange through. This will hold the pump for you while you nurse & will take advantage of the letdown that you get from baby.
PUMP BEFORE YOU NURSE: Your baby is always more effective than a pump & will be able to remove any milk that your pump didn't
NURSE RIGHT AS YOU DROP HER OFF & PICK HER UP FROM CHILDCARE: Make sure that your provider knows that she JUST ate & will, therefor, not be hungry for atleast another 2 hours & that you'll be picking her up at "X" time & to not feed her 2 hours (or a little more, depending on her feeding habits) before you pick her up.
Have you ever looked on www.KellyMom.com for info? It is the BEST site on the web for breastfeeding! Here are some quick links:
http://www.picosearch.com/cgi-bin/ts.pl
http://www.kellymom.com/bf/pumping/bf-links-pumps.html
http://www.kellymom.com/bf/pumping/pumping_decrease.html
Here's a very handy "calculator" too that might help to better determine exactly how much milk you'll need to pump for her while you're gone:
http://www.kellymom.com/bf/pumping/milkcalc.html
Hang in there! You CAN DO THIS!!!!!!
Good for you, by the way! I know that this takes a lot of effort, but it's, as you know, such a priceless gift. As I'm sure you know from your older child, this phase passes SO quickly! I mean, another 2 mos or so & she'll be on solids!
Hang in there!