For me, the best way to handle with overthinking is to do things that can help distract you! (Playing games that involve critical thinking: Chess, jigsaw puzzles? and etc ᕙ⁠(⁠ ⁠~⁠ ⁠.⁠ ⁠~⁠ ⁠)⁠ᕗ)

I hope these help you!