Oh giiiiiiiirl!
You and I could be sisters! I, too, get sick almost EVERY time I travel. I hate it! I was sick as a DOG on my wedding night (Vegas), and had strep through half of my honeymoon. My first trip to WDW, my dream trip of a lifetime (wanted to go since I was 12, went at 30 for my birthday), I was sick. Last year at
Disneyland I got so sick I couldn't talk and slept 10 hours a night. It sucks!
For me, part of it is the build-up to the trip, and then the release that comes from getting to a place where I can really relax and let go. I think all the preparation for me and hubby, all the travel arrangements, and settling business dealings before I go...and then get on a plane where every germ in the world is swirling in really dry air...how can I win?!
So I started taking Airborne this last year when I travel, and it has done wonders. It is, in my opinion, truly the air travel that makes people sick. So you need to take care of yourself there. Keep yourself hydrated, keep yourself bucked up on vitamin C and echinacea, and rest up.
Different remedies work for different people. Zinc never worked for me, but helps my Mom a ton. Echinacea is my savior. FIRST signs of feeling ill (and I mean first--don't second guess, do it!) I take it. Eat first, then load up. I take it in capsule form, and I take four with each meal of the day. Shortens any illness and reduces the symptoms amazingly. I recommend trying it to see if it works for you.
And as a last comment, hubby suggested that when you get about two weeks out from a vacation (if you can spare the additional time off from work, should you need it), seek out someone sick and let yourself catch whatever they've got. Boost your immune system just prior to going, and any illness that seeks you on your trip will have no chance! I am actually intrigued by this idea, and may try it. I am SICK of being SICK on my fabulous vacations!