Hello, I am 18 years old and I have an irrational fear of going blind… do you guys know any way to calm this fear ?

I “only” have -3 diopters of myopia (although the last time i went to the ophtalmo was last year but i still see well with my glasses) i am also astigmate but i forgot how many… I had a health problem so i stayed at home theses lasts months and i watched screens a lot (6-10h a day) so i guess this is why i am stressed with my eyesight… (i still do the 20/20/20 rule but i don’t know of it helps prevent possible damage.. I am very sorry for this post wich is kinda messy and useless but i feel like i had to vent to people who understand what is like :/ Thank you