Mac just “died” for a reason unknown

Good day yall! I'm using MacBook Air early 2015, which I updated to Sonoma 14.7.5 through opencore, and everything was fine

Though today I tried to open a screenshot from main screen, and the app preview just froze. Then I restarted the Mac and now it's lagging like sh8t... the dock is black and with the strange white border, like everything's corrupted, though I didn't change everything and processes don't eat cpu