Do you think my baby needs her formula milk changed?

I would suggest that you do. My daughter did the same thing. She would cry while drinking milk. It would break my heart. She would scream and cry later on. I later on found out that it was a milk protein allergy. I switched her formula to Infamil Nutramigen. It worked wonders. If you prefer Similac, they also make their version called Alimentum. These formulas come with the protein broken down already so your babies digestive system doesn't have to do it.