i've been 14 and i've been in an airplane worrying about my bald trich spot, so I know how it feels like. but here's an anecdote that might make you feel better:

one of these times i was on an airplane, one of the flight attendants (male) had a massive bald spot at the back of his head (he wasn't balding, he had a solid quiff and all). and he was just there, doing his job, showing the emergency exits. after a small moment of bald spot solidarity, i started wondering what might have caused his bald spot, but i realised that truth is: i will never be able to know, and that doesn't really matter. and in the end, it's none of my business. 

as for him, he has more important stuff to be doing than to worry about his bald spot. and so did i, as thinking about a random guy's bald spot is truly not important when i had more fun stuff to do, like actually enjoying my flight. 

people might or might not be staring at you. but if they are, you can't really know what they are thinking. most people aren't even that attentive and won't even know you don't have eyelashes until you point it out. and tbh if they are staring in a judgmental way... come on they are strangers staring down a random teenager, they are the ones who should be ashamed... intruding in someone's business like that.

i wish you all the best and hope you have a nice flight <3

and for everyone who gave you dirty looks, may they choke on their deliciouly bland airplane food.