My son is 22 months old and still has silent reflux. The silent basically means that they dont bring it all the way up. You dont see spit up because it only goes to the throat. It is VERY painful as it is basically stomach acid coming back up. He is on Zantac and has been since he was 5 weeks old. The only thing is that it is a chronic thing and not sudden.
With the age of your baby and the way you describe the incidents, I would look into Colic. Babies that eat really fast can also get too much air when they gulp. Then the air gets trapped in their belly and that too is VERY painful. A baby in pain usually wont eat. I would get the gas drops first and see if that helps. You can also burp him more often when feeding.
If the drops dont work, I would look into the reflux. Good luck