I am also a very private person and have a sister who is the exact opposite! She shares everything! We can run into problems when she expects me to share things with her that she would with me. Personally, I am not really interested in all the things she tells me and would prefer that she keeps it to herself! I am not really sure what the solution is. I think she is starting to realize that we are just different.
In general when you decide to “go public” on an issue, make sure to tell everyone who you know would expect to be told. If you are still keeping something private, and you don’t tell anyone, no one can decide for you that you have to tell. Also please realize that you cannot try to hide something that is impossible to keep a secret so people might be hurt by such things too.
In general, I think you have to try to do whatever possible not to hurt people but you still have to live your life the way you feel is right.