The hard truth is you may have written a stinker. If you have, chalk it up to a learning experience and move on. On the other hand, you may have written a masterpiece that just hasn't found its home yet. If you shell out $5,000 to a vanity press, you'll never know which it is. But one thing is certain -- you'll be $5,000 poorer and no nearer to your career goals.I do want to be a real author someday; I know this isn't the way to go about it. It's just painful having spent six years on a novel it seems that no one but vanity publishing actually wants.
If you really can't bear to see this book languishing on your hard drive, self-publish it. There's a lot of good advice for self-pubbing well (and frugally) in the self-pub forum.
But the important thing is to move forward. Have you written anything else during these past six years? If not, (and even if you have) start something new right now. Put this book away and don't look at it again until you've finished the first draft of another. That will give you a fresh perspective on its flaws and additional experience to use to fix them, if you still want to at that point.
Remember Yog's Law: Money flows toward the writer.
Hang in there.