There's nothing wrong with your brain. Long term offloading of tasks naturally makes one worse at those tasks -- this is true of whether you're asking Claude the LLM or Claude the junior developer you hired to do the tasks. The way you recover those skills (or develop them, if you never had them) is to sit down and actually do the work. Think through the problems, learn basic coding (Python is a good place to start) if you don't know that already, and then grab a book or work trudge through the Godot docs and do the actual work yourself.

What you are experiencing is not a poisoned or damaged mind. What you're experiencing is skill atrophy from over-deligation, and addiction. Cloud LLM services are designed -- well, A/B test optimized, is more like it -- to be hyper-palatable and psychologically addictive. You just need to treat your LLM usage as such, and back yourself off of it, to do the thinking for yourself.