Aw, you have a beautiful family! Congrats on your new little one and your decision to breastfeed this time around!
My first piece of advice is stop supplementing. It is affecting your supply - every time your baby is taking that bottle is a time the boobs don't make milk and don't know to make more. Newborns nurse a LOT. Their tiny tummies are about the size of their tiny fists, and breast milk is very quickly digested (much faster than formula because it is a perfect food for their tummies), so a breastfed baby will feed more often than a formula fed baby. Nurse nurse nurse nurse! The more stimulation your breasts get, the more milk they make and the happier baby is. If you must supplement with formula, then pump during the times your baby is eating the bottle so that your boobs don't slow production.
One way to combat a sleepy newborn is to change her diaper right before you nurse her, leave her in just her diaper and tickle her feet every so often. That's what I did with DD#1 and it worked.
I know it seems like she's eating all the time now, and she just might be, but it does get better in just a few weeks. You're also going to go through a big growth spurt in a few days, so be prepared for her to want to nurse even more often for a couple of days.

mama, you're doing just fine!
__________________
Kara (formerly wannaBmomma)
Co-Host of the Breastfeeding Forum
If one advances confidently in the direction of his dreams and endeavors to live the life which he has imagined, you will meet with a success unexpected in common hours.
--Henry David Thoreau

Vivian Zoe, Oct. 30, 2005
Irene Audrey, Nov. 13 2007