I really appreciate this question. It's a good one to ask yourself, you become what you think about and you only have to share what you think about.
Thinking about your illness may be beneficial to you. Focusing on it is a step to recovering from it.
What I think about. It's a good quesiton. I don't let myself be alone to think, almost ever. I believe I would think about... past days, past things said, redefining what things are, trying to put the pieces together of the laws of the universe, and then sometimes I venture back to things lost. When I'm feeling remarkable, I'm able to think simple things, "Wow, that sky is so blue and beautiful" or appreciation for colours, sounds, feelings, small things