This is my go-to link on weaning from formula supplements: http://kellymom.com/bf/got-milk/basi...rease-formula/
It sounds like it's been months since you were last able to exclusively nurse your baby, so you're going to have some work to do to ditch the bottles and get your supply back. Since the baby isn't doing such a great job of nursing, you're going to need to use a pump to boost your supply- and I don't mean a freebie pump from the hospital. You're going to want a hospital-grade rental pump (ideal) or at least a top-of-the-market consumer model like a Medela Pump In Style (new, not used; pumps have a lifespan just like any other machinery). You're going to want correctly sized breast shields to use with the pump. And you're going to want to pump frequently. Ideally, you'd pump every 2 hours during the day and every 3 at night, for 10-15 minutes per breast. But wait, you're saying, I never had good luck with pumping! I think that's the fault of the pump you were using. Hospital freebies are free for a reason: they're cheap, and cheap in a pump generally translates to ineffective.
As you use the pump to up the volume of milk you're producing, you're going to want to decrease the amount of formula you're using. You're giving your baby a HUGE amount of formula all at once. Breastfed babies- even older babies- generally eat only 2-4 oz when nursing. They make up for taking in small volumes of milk by nursing frequently; the average breastfed baby is eating at least 8 times a day, and often more frequently, until at least a year. This is actually an opportunity for you. If you're giving your baby 24 oz a day and 6 oz bottles, that means she's feeding just 4 times a day, correct? If you gave smaller bottles, you could a) feed her at a more natural frequency and b) give her many more opportunities to nurse and stimulate a good milk supply.
Okay, so nurse more, pump more, smaller bottles that gradually get smaller and smaller. What else? Well, there are herbal galactogogues (milk increasers) which you can try: oatmeal, fenugreek, blessed thistle. They can provide a small boost to some moms. Just don't expect them to create an abundant milk supply all by themselves. Pumping will do more for supply than any herb or drug. And there are prescription drugs which you can take. Reglan and Domperidone are gastric emptying drugs that have the side-effect of increasing serum Prolactin (the milk-making hormone) levels. Both have additional side-effects and are not for all moms, so discuss these drugs with your midwife or doctor before taking either one. And like the herbs, the drugs are not a substitute for hard work with the pump.
Another thing you could do would be to get an at-the-breast supplemental feeder (Medela Supplemental Nursing System or Lact-Aid- many moms seem to prefer the Lact-Aid). These devices are a little tricky to use, but by using a supplemental feeder you could make sure that your baby gets all her meals at the breast, and that might translate into less fussiness and frustration.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"