I can only speak for myself, rather than what is “normal,” but my blood sugar control certainly suffers when my sleep pattern is disrupted. Best examples I can think of, for me, come from regular travel for work. In addition to stress, I get about half of the average amount of sleep on work trips that I do at home. Even when I eat the same things (on the first couple days of travel when I can bring my own food, realistically), my BG is demonstrably worse after a redeye flight, when I only get 3 or 4 hours of sleep in a hotel, or have to get up super-early because of a time-zone shift.
I don’t know about the dizzy part and high blood sugar. For me, dizziness while exercising is usually a sign of a blood pressure drop, which is often about low blood sugar (for me). One of the reasons I’ve gravitated to lifting heavy weights for exercise or HIIT rather than extended endurance sports (cycling, running, etc.): for me, I have an easier time managing my BG and avoiding very low glucose and blood pressure. That low sugar/low blood pressure combo, I’ve figured out, is really scary to me: I’ve fallen off my bike (once), or almost passed out in the gym, and in both cases my BG was less than 60 mg/dL and my blood pressure was in the 80/50 neighborhood.
In both cases, eating some carbs helped to bring both BG and blood pressure back to “normal,” or at least close (my blood pressure always runs on the edge of clinically “low”). Is it possible that you overcorrected and were actually low(ish) during your ballet class? I suspect ballet would be pretty good at lowering blood glucose pretty quickly, and in combination with a correction may have led to a mild low or a drop in BG quick enough to cause some hypo symptoms. Is that possible?