This is Dr. David
it sounds like you have a bad pharyngitis infection of your throat.
it could be a viral or bacterial infection.
ideally, you should get a throat culture to see if there is a bacterial infection and see if you have strep throat.
why did you rate bad service?
I am not sure if your amoxicillin will help if you have a viral throat infection.
you should be gargling with salt water
and you might need a course of steroid therapy to help decrease swelling in your throat.
you should use benadryl on the flight to help you sleep on the flight