We're going to a very nice concert in mid-December. I want to fit into a dress I have by then. It's a small size 12 and I am currently a size 16.
Give me positive vibes that this is possible. Success stories under similar circumstances are also appreciated, as are tips on how to do it. Need positivity!

That way, if you fit into the sz 12, awesome! If not, you still get to feel good about your loss. 
Think positive...