FTM understanding “cluster feeding”

I breast feed exclusively to my 3 week old, in the past week between 9-12:30pm he acts starving, is on me constantly, comes off and cries inconsolably or acts like he can’t latch. Previous to the past two nights he was sleeping longer stretches, about 5 hours, in the night. Now he seems to be regressing from that and getting up every 3 hours like in the beginning. Our latch is great and during the day he feeds every 3 hours, left and right sides ranging from 20min-40min total and is completely content to come off the breast and sleep or be awake.

I’ve been told this is cluster feeding but I don’t understand it. I feel like he is just getting gassy and bloating himself from over eating. He doesn’t have a problem with gas during the day, just night when he’s cluster feeding. I’ve recently given him gas ease and it seems to help with discomfort but not helping the issue.

Help?!