Spit up in baby 3 months 25 days old.

Hi my baby is 3month 25days old. He is on combind feeding since birth due to low breast milk supply. He is taking similac advance iq . From past 1 week he is suffering  frm cold cough no fever. Doctor suggested kufril syrup and nasal drops. Am giving the same. Initialy he suggeted mucolite as there is no improvement after 5 days its given kufril. My problem is my baby spit up milk a lot altest 5 to 6 tyms a day. But doc saying that he us fine nothing to worry. But he cry for milk after every spit up. We give but some times no use. So pls suggest some solution to stop vomiting. At which month usually spit up stops in baby? As a mother i want my baby to stop spit up pks suggest some feeding techniques to avoid spit up completely