Firstly, Happy Halloween, y'all! Don't eat too much candy/possessed by a demon or something.
A couple of stories I had subbed came back to me because of unfortunate circumstances, so I had to submit them to other places. After I did that, of course, came the waiting. Waiting is horrible. You want to know if your story has a home right away.
The best thing to do while you wait is to stay busy. I do that by writing. I haven't been able to do that much writing in the past week because I've been "busy." (And by "busy," I mean finding other things to do other than finish a story that's almost done.) Writing helps get your mind off things, and it gives you more to submit later.
I have six things out right now. (I totally didn't realize that before I counted, though.) In the back of my head, Super-Neurotic Kristina is going a little bonkers, but Slightly-More-Rational Kristina is writing to try to get her to shut up. It's mostly working.
So, if submission anxiety gets you down, write!
(This is unrelated, but if you like books, and I assume you do, go check out the Twisted Library Press. They do good stuff, and they've published me twice, so they're not dumb.)