1) Write a story you believe in.
2) Patience is your best ally, even if it is annoying.
3) "I meant for it to be ambiguous" is code for "I don't understand why people tell stories."
4) Like any long term relationship, you're going to fall out of love with your novel from time to time. Find new reasons to love it rather than abandoning it.
5) There is no such thing as a muse. There's only you. Feel free to don a toga and strum a lyre if it helps.