What medecine should i take to calm myself down on a three hour airplane ride?

I am going on a airplane ride to florida in a few weeks. Even though it is only a 3 hour trip i need something becuase i am really nervous and i get really clostrophobic in airplanes. I just want something to keep me calm and not get sick. I am 16 years old and i will be with my aunt, uncle, and youger cousin so i dont want anything that will make me crazy or sleepy. If you could please give me a few options on something i could take, that would be GREAT! Thank you so much!