the pain is real, but caused by muscle contraction/cramp as a reaction to a sensation. You've taught yourself to wince until it hurts, and now contribute the pain to external factors. You've come to expect the pain, so it'll hurt.

The mind trick is right there: understand that you cause the pain yourself as reaction to a sensation and be mindful in situations where it might happen. You will find that the pain is caused from expectation and habit, this knowledge will break the cycle. Keep it up a for a few months and you'll untrain your habit a great deal.