I am going to suggest that you take this question to the orthopedic or occupational health forums. I have wondered myself whether carpal tunnel will explain pain proximal to the wrist-- or whether the injury would have to be proximal to the pain. Whether carpal tunnel or something else, decreased grip strength and pain with use are not normal in a healthy 43-y-o person. Without changing your behavior or treating the cause, the weakness is likely to progress, and it is often difficult to regain strength that is lost from chronic wasting of the muscles.