Low cal breast milk

My 2 month old feeds non stop all day. He does it partially for comfort but I was surprised to learn he wasn’t growing fast enough. He’s healthy, Head the right size, good length but only 9 pounds 12 ounces and today he’s 8 weeks. The pediatrician said because I’m feeding too often my milk is it fatty enough and I should only feed him every three hours for 15 minutes to build up more fatty milk but I love feeding him on demand And I’m nervous it is effecting my supply. I’m getting night sweats. I’m also nervous I just don’t make good enough milk. I take supplements, mothers milk tea all day, I’m hydrated... any suggestions?