Over feeding 2 week old??

I’m having a hard time figuring out if I’m over feeding my newborn. He started out in ICN getting donor milk, and a lot of it to keep his sugars up. Now I am exclusively pumping and he is eating around 2.5 ounces every hour and a half to 2 hours. BUTTT most of the time he still signals that he’s still hungry. He will scream and scream until I feed him at least another ounce to ounce and a half. So he’s getting around 3.5/4 ounces every hour and a half. He’s only 2 weeks old. I know you’re supposed to feed on demand but something doesn’t seem right. Seems a little excessive and he also is usually always fussy after eating. Like he’s gassy or something. Not sure what to do. I don’t want to over feed him especially if it’s upsetting his stomach, but I also don’t want him to still be hungry and fussy not sleeping.