I feel you. One of my dreams is to perform on stage, but ironically, being watched by many people is my biggest fear.
I think a light like that would produce harder shadows with more defined edges, especially if it's the only light source. Also, is the light pure white? Maybe a little bit of colour could help emphasize the message (depending on the colour you choose).
The girl doesn't really look like she is about to cry. She just looks a bit uncomfortable. Most people only look at an image for a short time, so you want to make your point as clear as possible. Of course, when I zoom in, I can see the tears in her eyes, but take a step back and see if it's still easily readable! You might want to push the expression a bit. Make her look like she really is about to break down.
One last word about the title. I get the reference, but most people won't. For them it will just seem like the title has nothing to do with the image. They might even think it's supposed to be someone thinking about their girlfriend who left them.
If you want to use a song title, I recommend using one that also works as a title of the image even if you don't know the song. Something like "On My Own" from Les Mis or even "I'm not that girl" from Wicked (then it would also mean that the girl feels like she doesn't deserve to be there, which could be an interesting touch).
Those were examples of songs I like, but it goes without saying that for your artwork you have to choose a song you're into.
Anyway, enough criticism!
I wish you the best of luck not only with the competition but also with overcoming whatever might be holding you back from achieving your dreams.
PS: You know Shoshana Bean? She's a legend!