When you get into a whine phase, seduce your book project back into the light by getting cocky, sexy, a tiny bit inappropriate, a little bit out there. Fake pure unadulterated confidence. You get better at flirting with practice. Make a fool of yourself. Nothing bad happens. (In whining, bad things do happen! You lose friends, you attract negative people, and you are blocked from taking in positive information. Plus you are driving without a license—who put you in charge?)
What's the cockiest thing you could do for you book right now? Pull the car over. Surprise everyone. What's the grand gesture, the wild thing? Infuse the relationship with an amazing shot of passion. Freak your book out a little. Make a list of incredibly confident thing to say about the book-in-progress. Make a list of intrusive but useful questions to ask other writers. Introduce a destabilizing element. Don't worry about rejection—flirting is always play. You aren't serious.