My baby spits up milk frequently, what should I do or watch for?

Hello, My 2 month and 2 week old baby regurgitates at every feeding? She regurgitates a very large amount. During the day, she is ambivalent about feeding; at times, she drinks really often, but sometimes she can stretch the feedings to 4-5 hours and spit up the breast. At night, she does an 8 hour feed. She has a dip in her forehead and her face is pale. She is in investigation for her vomiting, but now it's worse since 3 days & she doesn't keep anything.