Hi Laurakim,
First of all ,congrats on the birth of little Jack.
We had the same problem with Paige, she was really lazy , and it also took around 45 min - 1 hour to feed her. but it gets better with time.
All I can suggest is tickle him when he falls asleep, but also keep talking to him, whenever he seems to slow down, talk to him and encourage him, this used to work with Paige, its tiring but it does get better.
good luck