If during graduate school you lost a TAship at your institution; if you have now tried everyone’s patience here; if you are now being allowed to take certain classes so you can earn a professional qualification in another field; please do not address the professor who is kindly but painedly showing you how to register and directing you to other faculty’s classes as “my dear.”
Axé.
coldhearted scientist وداد 
Hey, I lost a TAship once. Believe me, I did not call anyone, anywhere, “My dear” after that!
Oh, dear!