I'm getting worried cuz when we we're giving our daughter Enfamil Premium- infant (yellow can), she…

I'm getting worried cuz when we we're giving our daughter Enfamil Premium- infant (yellow can), she was spitting up constantly and then started to projectile vomit, so we told her pediatrician and she switched get formula to Enfamil AR, it just seems like it didn't help.... She has been doing the same thing...I don't know what to do. My SO and I think she may be lactose intolerant because my SO is and sometimes she looks constipated. We don't know what we will do from here. She is our first child and almost everytime she spits up, I have to change her outfit and give her a bath because it's that bad 😕