Hey
@Tycksel - fellow dive master here. My sac is always higher when I'm working a class or even leading a dive for friends.
I just finished a trip to the Philippines where I was lucky enough to get paired with an ex underwater demolitions specialist. He was a big, fit guy who went through a lot of air. I don't know how many dives he has, but I guarantee you it was more than my 900. That guy was way more of a bad ass diver than I'll ever be. He was trim, quiet in the water, calm, unassuming, observant, etc. He dived a 100CF tank to our 80's and would sometimes be the one calling the dive even though the rest of us were diving with cameras.
Just keep diving!