When your problems are too big it's time to talk to your Parent or Teacher, or both:
Tell the person to "Please Stop"
(Use a calm, friend voice not a mean fighting voice)
Example "Please stop whistling, I am having trouble concentrating."
It they say "Ok", and they stop, say "Thank you."
Regardless of the outcome do not let someone else's actions control you.
Take three deep breaths and let it go. Go on with your life.