Just by the nature of the human immune system, next year will be better and as an added bonus, you'll be practically immune to any illness the people around you might contract.
I do take a cocktail of vitamins daily just because I believe it will prolong the quality of life I experience as I continue to age. I take a women's one-daily multivitamin, extra vitamin C, Calcium supplements, extra vitamin B, and Glucosamine/Chondroitin (for healthy joints and to help recovery of a particularly nasty joint injury last year). Generally, I don't get sick.
If you are regularly a germophobe, you could have set yourself up to have a weak immune system by lack of exposure to germs.
I think next year will be better, and within 5 years, nothing will be able to break your stride.
btw, what grade(s) do you teach? There could be a few specific kid-friendly tips that you might pick up from others who teach the same monsters you do!