When I get like that due to my anixety I'm definitely overthinker as well so I take 5/10 mins sit down first I tell myself OK few deep breaths now look around and tell me 5 things you can reach and touch then 5 things I can hear etc. Eventually it grounds me and definitely also works for me 🙏
Sometimes I can remind myself what’s really going on, sometimes I can’t. I feel your pain!
3 things that have really helped me with this (for maximum affect, do them in this order): 1- go outside and walk. Even if it's just around the block. Helps expend pent up energy and gain perspective. 2- brain dump: literally write down all of your thoughts. Helps to break cycles of ruminating thoughts. You can also talk to a loved one. 3- set 1-3 concrete and specific actions to help overcome what it is you're overthinking Hope this helps.