4 weeks old worrying update

so my pride and joy turned 1 month now after being born at 36 weeks she generally is such a content baby but recently she would sleep for an hour then wake up and she has soooo much gas like i literally think shes done a poo but its just fart after another and this is because i had to stop breastfeeding due to me being diagnosed with colitis and needing to start steroids so i had to switch to formula but now i feel like shes just never full at all is there such thing as over feeding? and what can i do to ease the gas apart from medications which i already tried.!!