I take Lantus slow-acting insulin every night, and Novorapid before breakfast, lunch and dinner. Before lunch, my sugar was 4.8; I took what I thought was the right dose for what I was eating, but now I'm feeling all fuzzy-headed and sluggish, and my sugar's up to 10.2. Is it OK to take another unit of insulin, or should I just put up with feeling grotty until my next mealtime?