The Beginning of Doubt

For the first day or so after finishing my novel, I was pretty ecstatic. And while I knew all of the things I still had to do to even have a hope of being published, I was feeling rather optimistic.
I am no longer feeling that way.
What if it's terrible, or at the very least, not good? What then? In my head I've already written giant red marks through dozens of things. Such as:
1) I don't think I've properly relayed a message or theme in the novel.
2) I don't think my characters have an onion amount of layers (Shrek reference, get with it).
3) I'm pretty sure I've forgotten to tie up some plot lines. And the big one:
4) I fear I've chosen a major cliche to occur in the novel, something that will turn off agents and publishers. But really it wasn't a choice. I knew right away the main character was guarding something and it only took writing to figure out what it was. Even still, maybe I should change the focus to something else...what, I have no idea. Maybe my secondary cliche of the narrator having lousy parents.
Really though, what hasn't been done these days? Aside from the off the wall fantasy stuff, which I have no interest in. There's a book on every sort of death, every sort of tragedy, every sort of teenage heartbreak event. The only differences are the angles the authors choose when writing them. It's certainly possible to take something cliche and make it original and interesting. The question is whether or not I've succeeded in doing that. Or will able to succeed in doing that based on the first draft. Time will tell.

I read in one of my numerous writing books that once you finish a project you should take a few weeks off from it so your eyes are somewhat fresh when you get back to it. So maybe things will clear up for me then, maybe the problems will stick out and solutions will come to me. Maybe it won't matter because I'll have won the lottery and will be able to take this at a more leisurely pace.
I guess the real goal now is to find a few people to read it that can give some kind of objective feedback. How terrifying. Why that's more terrifying than sending it to an agent, I don't know. I'm complicated with onion layers.