Eck, sorry things are crappy between you two. Her discussing your life with workfriends seems particularly irksome. (And yeah, only dicks would do that "lesbian from owen hall" thing -- and why would you want to associate with dicks?)
If you're comfortable with telling her, then come out. Be strong; she doesn't have to know. You're an adult.
When and if you're ever ready to tell her, do it with just you two, and stress that she doesn't go gossiping about it. Be confident in yourself.