Help!

My 3 month old recently started spitting up excessively. And I mean major spit up and over and over. We have an appointment to see her doctor but it's not for another week yet and I'm desperate. She spits up over 2 tablespoons worth of liquid EVERY time she spits up and will spit up 3 to 5 times within the hour. Most of the time it's clear liquid (unless she has JUST eaten) I've tried switching her to a specialty formula for frequent spit up but all it has done is made her not spit up formula any more and it's just the clear liquid now it hasn't reduced the amount she spits up.. does anyone have any information or suggestions that might help me?? Shes so miserable and I don't know how to help her.