all I can say is NO you don't want to take anything that will make it difficult for you to wake up if need be.
Just immagine you pop your pill and for some reason your aircraft needs to return to the gate. They will either not get you awake you you will be like a zombie and that might not be good for you.
Talk to you dr. about that anxiety and not something to put you to sleep.
You might want to consider one of those courses - they are very much better than "fixing" your body with chemicals becuase the pills do nothing for WHY you are afraid. The courses "treat" the problem. Sure they are expensive but you will not regret it.