I've turned into an absolute scrub. I can no longer CS, I can't win trades. My laning prowess has gone down the drain, and I've lost almost all mechanical skill (except stuff which you have to think about like Lee Sin or Gnar double bounce E with passive)
I haven't carried in an age. I'm losing my ability to do anything, even in normals.
If you feel like you're getting worse, don't worry.
You aren't alone.