(Could do with context: how old are you? Are you doing this as a job? As a student?)

> When I was a beginner I could solve any problem those "coding challenge" websites, but now I simply can't. I haven't stopped coding since then, I was doing it every single day and I still got worse. Maybe I am just overcomplicating things when programming.

How has this happened? Probably you are overcomplicating things. I would say that one good tutorial is better than a thousand bad ones. I would also say to skip video tutorials entirely.

Can you find a mentor or colleague? Or even just fellow learner? Not everyone is an autodidact, it's quite rare.