Hi Steve,
You came to a good place for understanding and similar experiences. I'm only average intelligence but I do understand the constant annalysing thoughts which never stop in your head. Mine are predominantly understanding my world, social failures/mistakes and why. I truly believe this is an obsessive behaviour/personality which appears common in people with neurodevelopmental disorders such as Aspergers and ADHD. This behaviour is not OCD in nature. A figure of 75% of people diagnosed with ADHD have a further diagnoses of Aspergers added. All you stats people don't ask me for the evidence!
My suggestion is to seek out a suitably experienced health professional in the field of neurodevelopmental disorders, such as, ADHD and autism spectrum disorders. Don't confide in anyone about your suspicians, you will have a negative response. Come to this forum too discuss anything on your mind.
Enviromental happenings can have a significant impact on your psychological pathology, such as, moving around a lot and not having a stable home. I find I'm overly sensative to enviromental factors which cause my thoughts to ruminate for long periods which is quite distressing.
Hope you find some answers here but remember we cannot diagnose, just illuminate you as to our experiences and similar behaviours.