Traveling far an over bridges !?

I went to Virginia beach last year and caught sever panic attacks when crossing back over the bridge to go home ..at the beach I was perfectly fine until on the way back.my stomach began to hurt from the previous night ..stopped at a gas station and had diarrhea ..got back in the truck after walking around for a few minutes than headed towards the bridge.I was in the car with my aunt cousin and my parents but just because my aunt was driving I was scared I couldn't tell her to pull over if I gotten sick.we ended up at the end of the bridge! Funniest thing happened..a car broke down on the bridge! I got sicker by seconds shaking crying etc.my iPod was dying so i had no music for distraction ..n no meds. Everyone got out the truck to walk around while waiting for the broke down car to get on the move!I took a half of xanax and that only made my stomach feel worse! Took the other half and I got high! But it was a good high because I was calm and relaxed and not scared anymore.the rest of the trip was fine! I plan on going back this summer but I have no suggestions on what I should do to prevent the anxiety !plus my new bff wants to go but having these attacks are pretty embarrassing! What can I do? I need extreme help! Thanks alot! I need good answers please ;)