Milk Protein Allergy?

Are there any Mommas who's LOs have a milk protein allergy? If so what were their symptoms? At first I thought my LO had bad reflux but I'm beginning to think otherwise. He is exlusively formula fed as I tried to BF and couldn't produce enough even with trying everything my LC suggested and doctor. He often sounds congested, especially after a feeding, frequently gassy, he spits up after every feeding, has a red bum that won't go away with any cream I've tried and he cries every evening from around 6pm to 9pm until he goes to sleep, he also has frequent BMs (usually 3 per day). He was on Kirkland formula when all the symptoms started, I tried switching to Enfamil Gentlease and he was projectile vomiting and had green runny poops. So now he is currently on Similac Partially Broken Down Protein for the last few days with all the same symtoms...