You may lose a few friends along the way, but the ones who remain are the ones who will stick with you through thick and then to the very end! I have about 4 great friends that I have been friends with since middle school and those are all I plan to keep!
If you don't know what to say to someone in chronic pain, don't worry. You don't have to say anything! Just be there and listen. No platitudes or advice; we just want you to treat us the same way you did before we became sick- as your friend.