My peak rating was above 1500, but recently I've been constantly losing rating, and now I'm around 1200.

The frustrating part is that I can independently solve some 1900+ problems, yet I often struggle with problems rated 1200 or even lower.

I spend a lot of time thinking, analyzing different cases, and trying to derive a solution, only to discover that my very first observation was wrong. Then I read the editorial, and the key idea seems ridiculously simple.

I'm comfortable with problems where I can gradually derive a solution, but I often get completely stuck on problems that require one clever observation or greedy trick.

I've solved hundreds of problems, yet my contest performance seems to be getting worse.

Am I overthinking? Am I practicing the wrong way? Or am I missing something fundamental?

I don't think I'm that stupid, but lately it's really starting to feel that way.

Has anyone experienced this? How did you overcome it?