I too am a little surprised to see traffic this slow on this board!
I applied to Yale GEPN last year, got in, and decided not to attend. So I have survived what you are going through now.
My advice: You can't change the past, and you have no idea what they want. The one thing you have now that is totally within your control is the essay.
Also, the process of writing the essay and refining your thoughts about why you want to do this is really important, just for you.
They are deadly serious about taking every question, and every piece of every question, in order, and don't leave any out. And make it sound pretty! (I had to go back late in the process when someone asked what I thought at the time was a silly question: Was it OK to list hobbies before travel in the last question, or whatever. "She" said no, you better do it juuuust like they ask. So I was the silly one.)
Those Friday online chat sessions are great, by the way. You can sign up for them, and have one or two admissions people answering your questions, telling you about things that aren't on the Web site. There are usually only a couple of people on them early in the season. Look for "admissions events".
Also, choose the specialty you're applying for carefully. At the end, at some of the schools I got into, it seems like a few people wished they'd chosen different specialties. Go for the one you really want and can speak most passionately about.
One more piece of advice: Let the schools make their decision about you. Don't you reject yourself for them. We were told that about half of the people who started the application never finished it. All of these schools could make their admissions decisions in a week if they just picked the top GPAs and scores. But they don't, do they? So work on that essay and tell them what you have inside.
Choose the school that is right for you, that you can afford. Give yourself options. Take some prereqs while you're waiting -- you'll at least get to waive Anatomy at Yale. Or you might find you hate it, or you love it and want to be a pathologist.
And remember that there are so many ways to have the career you want. Yale is an amazing place, but it's not the only place.