Hi Sophia's mom,   It seems as though you are having quite a rough time. I hope things get better for you soon! If in fact your daughter does have thrush, and it sounds like she might, the Prevacid is not going to help resolve that. Thrush is a fungal infection and needs to be treated with an antifungal medication, such as the Nystatin and diflucan that you used previously. If your daughter has GERD, the Prevacid may help, and she may be able to better tolerate the medications that made her vomit before. Either way, she probably needs to see a pediatrician again in order to figure out what's going on in her mouth, as well as the best way to treat it. Good luck with everything!   Casey