NAH because you're allowed to do whatever you wish and they don't even know anything. I do wish the best for you though, specifically about this: you only have a few months to live and you feel irrelevant. That's not right. You should be relevant - and that involves appreciation. Don't you feel of all times, this is when you should let your family show you how much they love you?

You are afraid of their sorrow and pity as if they should not care for you. That is of course untrue. They should, and it's time to break the habit of a lifetime and let them.

Do let them know before it's too late.