https://privnote.com/Yy8HU2TR#WOSQOlXM0
this is how it works, create a note and once your done click the button that says "Create note" you get this link, that can be viewed only by 1 person before it gets deleted. also if you fear this isn't secure enough, to ensure it doesn't get read click on "More options" before creating the note, and add your email account, it's private and will send your email a notification if someone opens your note you created.