Baby spit up


My son is going to be a month old tomorrow and he has been switched twice to different formulas and he is spitting up so bad and so much where it seems like nothing is helping. It’s not like just a little spit up its like a fountain and sometimes comes out of his nose too when it happens I have tried slowing how much he eats at a time to give him time to digest it I’ve tried keeping him in a upright position for a longer time before he lays down. I feel so bad his doctor isnt open until Monday to call them. Anyone have suggestions or ideas of what can help. Please 😬