I forgot how to use the stairs and I don't know what's happening

This started happening 2 years ago. Whenever I use the stairs (usually climbing up), it's like the stairs shift together, like I forget how to use my legs. I tripped almost every time and get a mini heart attack. Whenever I go down the stairs, it's a bit easier and sometimes I can go fast. I used to be able to go up and down the stairs extremely fast, now I can't even go slowly without my vision getting blurry and doubled. This will sound so dumb but it's like dyslexia but with stairs. I always have to kick the wall of the stairs with my toes in order to BARELY navigate. It feels so embarrassing, especially since I'm kinda big.