My heart just breaks for you and your LO! I am so sorry you're going through this!!
I would definitely take a hard look at the meds she's on... I'm assuming reflux medicine? You may need to increase the dosage (Zantac in particular I know is weight sensitive, my LO used it until he was 1)
Does she have any other symptoms, I'm wondering about MSPI (milk soy protein intolerance). Sometimes reflux can be a symptom of MSPI. My DS3 has this and he was so unhappy and uncomfortable until we figured it out. I am BFing, and had to change my diet removing all dairy and soy from my diet. But since your FFing, you may need to switch to a formula that your LO can digest, especially if she's having trouble with the full protein chains found in "regular" formulas. You could try switching to a hydrolysate formula like Nutramigen or Alimentum. They are milk based but broken down into partial protein chains. This may just be enough to help your LO digest the formula enough and settle her stomach.
That being said there are some more sensitive babies who need an elemental formula, which is completely 100% broken down into free amino acids (the building blocks of proteins) so there are no proteins for your LO to digest, it's already done for her! (What makes Neocate special video: http://youtu.be/Hoj4DtjE4zM)
Talk to the doctor again and really push for your LO, you are her advocate and her voice, if you don't feel she's getting the attention she needs than switch to a different doctor.
Here is some more info that I found helpful:
Hang in there!!!