Sammy has given you some great advice all the way around. I just wanted to echo what she said about not mentioning the addiction & etc. Many in PM today are on the edge of their seat already. I wouldn't give them anything that could be perceived wrong....Especially at a first appointment. While your intentions are good, it may backfire and ultimately hurt your need for effective treatment.
Overall, I would try to stress how the pain effects your life and how it impacts you daily. I would explain in detail what happens while you are at work, and how you cope at home.....Especially the part about your "dead day." I would also tell him about the letter your friend wrote and how others apparently see you much differently than you see yourself....That you haven't realized exactly how moody you have been....And it's due to the pain.
Best of luck at your appointment.