Whatever you do, when you go to see your Doctor to ask for an authorization for medical Cannabis - DO NOT ASK FOR HIS OR HER KNOWLEDGE ABOUT, EXPERIENCE WITH, OR OPINION REGARDING CANNABIS!
Doctors do not receive any medical training regarding Cannabis Medicine unless they seek it out themselves, most are too busy for that. Asking questions like the these 1) expose your Doctor's ignorance and 2) provide opportunities for the Doctor to wade in with opinion and bias. Without formal training to know how to answer these questions, you put them on the spot, make them uncomfortable and your chances of success decline seriously. Questions like these are likely to bring a quick end to the Appointment.
Instead, try this, be enthusiastic, tell you Doctor that you have used cannabis medicine and tell her how it alleviates your symptoms and provides you with a much improved quality of life. Then tell him that your position is sadly illegal, you could be criminally charged for using cannabis as medicine. If s/he will just sign this simple form, your use will become legal. Ask for your Doctors help and for their trust in you, do not ask their opinion!