T.M.
Here is what I'm thinking. He equates the doctors office with pain. How close is the doctors off? Can you stop by the office to get a lolly pop or sticker or a hug? He needs to know that it doesn't always hurt to go to the doctors office. See if you can get the office staff to play along. Have him wieghed and measured. How do you feel about going to the doctors office? A reward for not pitching a fit would also help. It would give him something to think about other then the fear of pain. That and lots and lots of hugs,and snuggles. Hold him in your arms the entier time of your appointment. This fear is real and he has good reason for it. There are all those shots. I hate them to. Good luck..