Little Hungarian!!

Does anyone else have a little Hungarian? My little man is 5 weeks old today and eats like a grown man.. just kidding but that's what it feels like. We have to supplement formula to keep him full in addition to breastfeeding every 3 hours max. Some times, it's every 30 mins. My question is how to get him to nurse longer? When he eats, he is eats for an avg of 5 mins and is done and out like a fat kid in dodgeball. There's no waking him up. Change his bottom, nothing... wipe his face with a wipe, nada... ladies I'm telling you, he is DONE!! what can I do, if anything, to encourage him to eat longer so that he's full? Thanks in advance!