This happened with my 2nd daughter all she wanted to do was sleep I was back and forth to the doctor scared but everything was OK.
Can you take him.into the hospital and make an appt with the lactation consultant? They ate usually more than willing to help whenever you need it. Also try expressing some with a pump or your hand and feeding with an eye dropper. He might not be getting enough and is not tired from not eating. If he gets some.into his system it might wake him up and give him that boost he needs to latch vigorously. Make sure he is having enough wet diapers too. That will tell you if he's getting enough too.
I remember the nurses saying 2-4 hours needing to be fed with mine. Sometimes i went over from exhaustion but they will get in routine ayer a while. I think it's great to get 5 hours of sleep at night. If your concerned you should call the pediatrician and be sure. And how does he eat during the day? If you have a pump it helps to collect that milk he's not getting to. I know they start hurting. They know when it's feeding time.
Try hand expressing a little milk so he tastes it as soon as his lips touch your breast. Sometimes newborns don't want to work for it unless they know it is worth it. Removing all of his clothes may also help to fully wake him.
Try changing his diaper and stripping him down only to the diaper right before you try nursing to wake him up also the skin to skin helps I have found with all 4 of my boys in the early days after birth!
Are you giving him pacifiers or bottles because those can cause nipple confusion and baby to sometimes reject you?
Maybe you are producing very good quality stuff?? Get hold of your local la leche league, they are always happy to help. There's a breastfeeding forum on this ap i think too.
I Wake Him UP But He Doesn'tWant it
Are you waking baby or waiting for baby to wake because you may need to wake them until they get into a routine? If baby falls asleep while eating you can try things to keep the baby up, switch sides or they may be full. As long as they are getting something, it's better than not feeding at all.set an alarm if you need to, but at this age they need to eat often.