There is a forum on here called 'Fitness, Exercise and Sport', where loads of sports people with diabetes thrash out the problems of controlling their blood sugar, avoiding hypos, and carrying on with their sporting lifestyle. I'm sure you will get help from somebody there for dealing with your current problem of avoiding hypos and hypers when you're teaching your classes. Google TeamBG as well as this would probably be a useful website for you too. Best of luck, ...
and welcome to the forum, by the way!