After an accident two years ago I developed some tics and abnormal compulsive behaviour that make me feel like a real nutcase but none of the tricks I find online have done anything to help.
I've tried inflicting light pain to myself when it happens as a sort of reverse Pavlov bell, I've tried deep rationalization: analyzing the feelings to their root as a way to take away the associated emotions, and lately I've been trying repeating the opposite of the way I feel as a way to try and cancel the thoughts. It is really hard retraining the brain it seems.
It's given me some really interesting insights on trauma, though. It's hard to empathize with things you haven't experienced, I used to feel people were weak who were traumatized by life experiences that I felt were not all that bad compared to some of the things I and other people I know have been through. But it turns out it's not about the magnitude of the harm, it's more about the way your brain interprets it and the false causal patterns it forms from your experience.