If he's on breast milk just remember you can't really over feed a breastfed baby! They digest breast milk very rapidly and even if throw up a little they still get plenty of nutrients because it is absorbed so quick 😊 he also may be wanting to comfort suckle for many reasons like growth spurt or not feeling well or to increase your supply, so I would suggest latching him to the breast so he can control how much he gets!

My daughter did that a week ago she was going through a growth spurt so she was constantly eating every 1 1/2 - 2 hours and today she's 2 weeks old and she's been doing that again today every 2 hours but it's turning into 1 1/2 hours so I think she's going through another growth spurt she's also very fuzzy and hasn't slept much all day. Not sure if that's what's going on with your baby but it's a high possibility