Been there. Done that. I call it “lock-up”. Sleep studies and half the prescribed dose of Trazadone helped.
Overthinking isn’t the problem in itself: lack of something to stop it is. (search “dopamine, MTBI, whiplash and fMRI” ). When society’s primary means of increasing profits is to disconnect people from reality so they buy more uselessness, is it any wonder that when left in our own mind’s world of fears and images, we get caught up in circular reinforcement and paralytic fears..begging for a chance to buy something to distract us?
Civilization itself removed humans from their natural world, making brains feed on claps and artificial rewards, and unafraid of real consequences of being allowed to dream up models of reality that are infinitely rebuilt. No immediate feedback that a tiger will come along, and no constant hunger driving us to move and take action.
Civilization causes atrophy of individuals’ Executive Function in favor of authority and group conformity. Without a group, few are adapted to individually act in their future best interest when profits are highest if we don’t.