I am Woman. Hear me ... Choke?

So, I've been in this major rut lately. I just keep doubting myself: my looks, my smarts, my talent. It's a real bummer. All of a sudden, I care how other people see me, and it's driving me crazy. It's been little comments made by friends that have gotten under my skin and into my brain. Comments like : Are you trying to put on weight?
So, I worry about calorie intake and diabetes and I change my clothes 3 or 4 times in a morning. I obsess. But it's not just that one area that's got me on the Fritz. It's also this conducting class I'm taking. After the vocal catastrophe of 2005 when I had a semester of deployment, depression, and Dr. Schultz to deal with, I now seriously doubt my musical talent, as in whether or not it ever actually existed. And now, as a conducting student, it is my responsibility to teach, correct, and conduct a choir for a grade and I can't help but think, why should a group of students, including many music majors far more talented and better musically equipped than I, listen to me? What do I have to offer? And the answer just comes up as: BLANK.
I feel so utterly vulnerable and naked before a society which values a certain type of physical beauty and virtuosity that I do not posses. So, why do I all of a sudden feel this need inside of me to try to live up to these impossible standards? If I were ten pounds lighter and sang like Kathleen Battle, I would not be any more content, because there would always be someone prettier, smarter, and more talented than me. Or perhaps I would not be happier because joy does not come from looks or talent or fame or knowledge. No matter how hard I strive for each of these things, I find myself just as empty and discontent as I was to begin with. So, what's the solution? What's the point? How can I be happy? Perhaps it is time, once again, for me to stop trying to live for myself. I need to fill that emptiness with One who won't leave me empty again.

Does the world seem gray with empty longing
Wearing every shade of cynical
And do you ever feel that
There is something missing?
There's a God-shaped hole in all of us
And the restless soul is searching
There's a God-shaped hole in all of us And it's a void only he can fill
~Plumb