A dumb or idiotic question, but sorry!

I'm sorry, but after the game, when you do the "game analysis" in the current model, a classification of each player appears, would that be their playing strength in that match?

I ask this because I have an incurable disease, I am undergoing treatment for it, Bipolar Disorder, and there were games where I played seriously, I scored 1450, but there were games where I played badly, but they were not short games and I only scored 350.
And I was surprised by the difference, because when I am down I play badly, when I am in "Euphoria" I play above my level and there is my regular or normal.
Thank you in advance

Yes. I believe it is your performance rating on the analysed game

Yes. It means that the game you played was of that rating level.
Sorry to hear about your condition.