To eat or not to eat!

My 5 week old recently started to fuss and cry while feeding ( formula- bottle feeding) and he would choke on the milk and cry. But would still want to drink. I would pull the bottle out he would calm down for a little then start to cry again for bottle , I give him back the bottle and he does the same. I've tried burping him, gave him gas relief... I'm really sad because he seems to be in pain but not sure what it is