Hello to all new mums

My baby is 2 weeks old and just came back from hospital adter 14 days in there...we are trying to get used to beeing home. I breast feed him first..but ever since beeing in hospital he takes a top up bottle of formula...sometimes even 90 ml..but of course i would not know how much breast milk he had...and almost every time..even after a couple of good burps ..he does this projectile vomiting and takes most of it out...im so worried..cuz then he get hungry again and the cyle repeats itself:*(. So worried something is wrong...do any of u have this issue? I need to see the doctor anyway..but not sure they will help. Any advice?