This sounds more like abnormal psychology to me which is out of my domain of expertise. Maybe a veteran meditation teacher or psychologist would know about this sort of thing.
All advice I could think of giving is only based on normal psychology. I'm not sure if you could use this dysfunction as a stepping stone to enlightenment (identity as witness), since addiction to thinking is the delay for most people. Or if you have to correct what went wrong somehow just to get yourself back to normal. If it's ruining your life, and it sounds like it is, consider seeking out a professional and see if they know what this is exactly.