Is there a remedy or cure for this? (please help)

when i was younger (9) i was learning that i had to put deoderant everyday so i would get a habbit of it when im older.

My aunt lived with me at the time and she likes to expiriment with new stuff everyday and she doesn’t like to shave so she bought this product that has chemicals in it but its as hard as a deoderant and it looks like a deoderant aswell.

and while i was learning that i had to get the habbit of putting deoderant on everyday… i accidently grabbed that deoderant looking hair removal thing ( my deoderant and that chemical thing was next to it)and i was in a hurry and i didn’t check if it was my deoderant and i just put it on and i ran out the door….

later on that day i started to get burns and aches in my underarms and they hurt so much…. till the point where i had a fever and i couldn’t stand it and i ran into the schools bathroom and i washed my underarms and when i noticed i didn’t put on deoderant but that other thing…. it was too late the chemicals burned my skin and as if it was cooking my skin and it turned black and it bled alot

i had it on for 3 hours

now im 16 and my armpits are gray-ish and i really don’t like how it looks.

is there anything i can do to get my normal skin color back ?
or
is there anywhere i can go to fix this problem i have?

please help… i want this gone