Now what??

So I did it. I carried my manuscript all the way to the post office, paid for the postage, I added a SASE (well a postcard per the publisher’s request), sealed the envelope, and handed the "precious creation" (precious to me that is) to the postal worker, who than tossed it in a large bin full of mail.
Bata-boom! It is on its way to the publisher.
Now what?
Write more, re-read my query, re-read my submission, wait some more, write something fresh, but I can’t write, my mind lingers back to my submission, oh no, now what?
It is like I am in limbo now, so I ask again now what?
I am writing fewer than 500 usable words a day, and I am in need to challenge myself on redirecting a plot I have been working on, but somehow am stuck in the middle of everything I touch, so now what?  
I exclusively sent the MS to the one publisher, and I know they receive 1000 submissions a month, and my “precious creation” is within the slush pile patiently waiting its turn to be picked up, and read, and alas’ accepted to be put in print for the world to see! Well that is how I see it sitting within the slush pile.
Letting go of projects that have been released to the world can be a challenge in itself. I had worked on this project for two years everyday, I somehow thought sending it out would help me to move on from it, but I find myself still revising, and critiquing the “precious creation.” I am not neurotic, well maybe a little; however I am not hovering around the mailbox, but hope for a reply does cross my thoughts each day. The submission guidelines stated a reply within a six month period, and so I know this wait will be long, and given the statistics that 98% of MS that are submitted are rejected, well this leaves for a long limbo feeling that could lead to a stinging rejection, so I ask again, now what?
Yes, rejection is a part of the writing life, and yet optimistically 2% of the time, so is acceptance, but mostly I think a simple reply from the agent or publisher is really what writers are waiting for, I guess the wait it is on,
so now what?