FTM Help!!

My baby is almost 3 weeks and he’s been sleeping 4-5 hours during the night which I am super grateful for but my doctor keeps telling me I need to wake him up and make him eat. When I do wake him he is absolutely not interested and it’s just miserable for both of us. He eats just fine when he wakes on his own at night and other than that one long stretch he wakes every 2.5 hours like clockwork eats, poops and goes back to sleep. He has the right number of wet and dirty diapers. He passed all of his newborn tests at the hospital except for one low blood sugar reading. He was 9lbs 4oz at birth and was 9lbs when we left the hospital. He maintained that through his 2 day and 1 week check and then at his 2 week check he was over 10lbs. The lactation consultant at the hospital had me supplementing at the breast with formula but that only lasted 2 days at home before I said to hell with it and we went back to just nursing. I nurse and pump but I’ve only given him 2 or 3 pumped bottles in the two weeks we’ve been home. The doctor also told me he needs to be nursing for 20 minutes on each side but little man nurses a max 15 minutes before either popping off or tearing my nipple to shreds with his thrashing. We burp switch sides and he usually pops off the other side in 10 minutes or less and after a good burp falls asleep.

Where he is gaining weight and sleeping okay do I need to wake him? And do I need to try to get him to nurse longer if he seems satisfied?? My lactation lady also told me that he doesn’t need to breathe out his nose while nursing so I’m kind of doubting the advice she gave and would give. She’s unfortunately my only local option.