First time prescribed Xanax

My psychiatrist prescribed me 0,5mg Xanax for my anxiety and panic attacks. She told me to take it whenever I feel anxious (so it’s not for everyday use )

I have never taken Xanax or anything like that before.

I have a flight coming up this week and I’m usually nervous and I’m thinking of taking it for the first time.

How will it affect me?

My only concern: I just don’t want to be falling asleep and feel sluggish because it’s a long trip and I still have to take trains etc.

Thank you in advance ❤️🙂