I do not want visitors. Am I being unfair?
No. Visiting is often more for the visitor than for you. Being cheerful for other people is real work, and you have none of that energy to spare.
You are allowed to say not this week, or twenty minutes only. You can ask one person to pass the news on, so you are not telling the story ten times. Giving someone else that job is a fair use of the people who want to help.
Written by two physicians. Checked against patient information from the US National Cancer Institute and Cancer Research UK.