Hello I am a new mother and I am worried there might be something wrong with my daughter. She was breast fed for the first two weeks then I had start to substitute formula because she wasn't gaining weight. I have had to switch her formula four times in the last six weeks because she throws up after almost every feeding and is constantly hungry, I was starting to think maybe it was the milk base so I recently switched her to a soy based formula, she has been on it for four days and she is still throwing up, it isint like normal spit up It seems sometimes like it is more then she is eating. Any suggestions to what the problem might be?

Optional Information:
Female, Age: 22, Michigan

Already Tried:
Similac with breast milk nutrients and iron Good start with breast milk nutrients, iron, and comfort protiens Enfimil AR for babies that spit up with breast milk nutrients and iron and now using Similac soy formula with breast milk nutrients