Overthinking is probably the bane of my existence. If I were to express the thoughts that run in my head daily, they would overwhelm people because they typically overwhelm me. This weakness messes with my sleep pattern from time to time because the thoughts are always running. I mitigate this weakness by writing, which helps tremendously with getting all my thoughts done. Also, I make it a point to read fiction, which also helps with the calming of my thoughts.
Overthinking in how I relate to others has much to do with making a point as concise as possible instead of giving a dissertation on everything that it entails.