"Dear Plus-Size Clothing Store,
I'm sorry, but it's over between us. I realize that we've had a long and complex relationship throughout the years, and although you've seen me through many (size) changes, I feel it's for the best that we make a clean break.
For far too long, I've relied on you to outfit me for any occasion. I think my dependence upon you was born out of comfort -- I knew that I could always find something that would fit me, and for a time, it really didn't matter what that was.
Those times are over now. My closet is full of your fashions in every possible size. The things I have currently will be more than sufficient to sustain me through my weight loss, and I simply cannot justify spending any more money on clothing (especially when I have no intention of fitting into it a month or so later!)
Instead, I will be saving my money so that I can go on a *major* shopping spree once I hit my goal weight! Until then, I will wear what I have, and if I really truly *need* something, then I will buy it at a "regular" store.
It's been a good long run, but it's time for me to move on."
I couldn't have said it any better.