I still would try to be positive, even if I had a terrible chronic thing that was hard to treat. It's just not in my DNA to be gloomy about this. But, based on my mom's experience, (a terrible life threatening disease that ended in a failed liver transplant), she was positive until the end. She was and still is my role model. At one point they hospitalized her, to get her higher up on the list for the transplant. She actually was not as sick as she was "pretending" to be, and spent the time participating in a program where she helped teach medical students and residents good "bedside manner" and listening skills.
That's how I want to approach anything that comes my way.