You can always write down everything and have them read it first before you start talking about everything. That way you won't get emotional talking to them about it before they learn all about your situation.
Yes! Write the doctor a letter and keep it as short, sweet and "un-whiney" as you can. Give him some time to read the letter and then discuss it with him. The worst thing any pain patient can do is to go in and demand a specific treatment from any doctor. You have to give your doctor time to get to know you and your case and build some credibility. We all want instant relief, but it generally doesn't happen that way. Matter of fact, expecting total relief from any treatment is unrealistic. No doctor can guarantee to make you pain free. Medical science hasn't progressed that far yet, so the most you can hope for is something that will make the pain dull enough that you can have a life.