Ok, so you sent off that draft, or you dropped it in their mailbox, or whatever.
It ain't perfect; maybe your cover letter ain't perfect; maybe the list of things you would have liked to accomplish is longer than the work you submitted. But you submitted it.
And you get to wait to hear back.
What do you do in the meantime?
You could start by celebrating a little. Sending off work is tough. Acknowledge what you have accomplished for a moment or three before you go back to working on the things you haven't accomplished. Build some good feeling in your life by recognizing what you get done.
But then you want to get to work again. You don't want to rest on your laurels too much; whatever the feedback you do get, you want to be able to have new work accomplished for any contact with your professors. Don't focus on the things over which you have no power (what the reader does with your submission); instead keep working. If you have been productive while waiting for your feedback, you're probably going to feel better able to handle whatever feedback you do get. By building your work, you create something to feel good about rather than simply waiting and depending on the feedback to make you feel good (or bad!).
What you don't want to do while waiting is worry about what the reader will say. That will be revealed soon enough. Usually. When you get the feedback, that's when you process it, and deal with the good and the bad. While you're waiting, you're either not thinking about it at all, or you're reminding yourself of how the feedback will provide valuable information that will help you--even if the feedback isn't good (see my post from a few days ago about preparing for feedback).
Ideally you will hear back from your committee sooner rather than later. And then you'll have feedback.
Too often, we'll wait a long time for feedback with no result. Don't be thrown by this. It's reasonable to check in to remind your professor about the submission and ask if they'll have a chance to get to it. You might also try telling them a little about what you are working on while waiting, or even submitting something. If you're not working while you wait, that can suck up a lot of time. Don't depend on the readers; take the initiative. The harder they see you working, the easier it will be to get feedback (usually).