Tongue/lip tied baby

Amanda • We are a blended family of 7. This will be our first together. Super excited.
So I found out yesterday that my one week old is tongue/lip tied. After having so much difficulty and pain for the past week I finally got an answer to why. He had went down from 8.5 to 7.7 which is a little concerning especially if it goes down more. So on top on him being monitored weekly the doctor suggested I use a nipple shield to feed him until he goes and gets his tongue clipped. It works for the most part but he still ends up falling asleep within 10 min at the breast just like he would do before. Is he just not used to the shield and I just need to break the habit of him falling asleep?