Wow, thank you all so much for your empathy and support

You're really great!
I definitely feel the overthinking has been a form of self-preservation.. It's like, if I stay in my head, then no one can break my heart.. Because the way it was blown to smithereens when I was only just beginning my life was way too much for me to handle back then. There was no one to explain to me that it was my parents with the issues and that being abandoned emotionally by them had nothing to do with me..
I think part of healing is to understand this now, as an adult, and then letting it go.. I don't want to hold on to the overthinking anymore because it's actually making me ill not listening to my body's messages about needing to eat, sleep, exercise..