Can I reverse the cognitive decline caused by constantly being on screens?

Long story short I've been on screens for most of if not all of my free time for the past year or so. I've noticed that I've been experiencing significant cognitive decline in several different ways, I wont list them here just know they are exactly the type of symptoms you would expect. My question is, could I reverse this cognitive decline in some way or is it too late (im 18 for reference). If it is possible, how? I mainly just want to be able to get rid of this mental fog I have, be able to focus, and be more emotional.