Breastfeeding fighting

Alyssa

My 4.5 month old has been latching for a minute then unlatching and throwing a fit. He doesn’t do it at night and it’s only been recently since I’ve started giving him a bottle after feeding that has 0.5oz of formula in it as per the dr. I’ve tried stopping and burping him then trying again then he fights it. What does this mean? Or any advice is appreciated.