Truth and what you believe matter naught. If you said out of pure malice I had a contagious venerial disease or was a wife-beater or pedophile, holding me to public ridicule, even if true you'd likely lose.
Defamation (libel or slander), by definition, must involve a factually false statement. If what you write is factually true, it cannot be libel. Also if what you say cannot be determined to be factually false (if for example it is an opinion) then it cannot be defamation.
I might invade your privacy by telling others that you have a disease, and be liable for invading privacy, but it will not be libel.
