Fellow writer, I get you. I know exactly how lonely it feels to toil on a novel, wavering between thinking the story is going to be a blockbuster or a bust.
But as snobby as this might sound, I have a policy of not critiquing or editing other people's writing. The reason is partly pragmatic: I don't have the time. I even quit the writer's circle I belonged to---all of us competent, published fiction writers---because it cost too many hours to read and critique everyone else's writing. I've got my own tales to tell.
You see, ever since I got lucky enough to get published internationally (which led to giving workshops on the writer's craft and teaching a graduate-level fiction course at FSU) dozens of strangers now approach me every year to read their short stories, novels, memoirs, essays, etc. I've had people call me on the phone from out of state, asking if they can mail me their manuscripts for my comments. My favorite absurdity (encountered more than once) is when people say, "I've got a terrific idea for a novel, but I'm not a writer. I'll let you in on the idea if you'll write the book and promise to split the profits with me." Years ago, I decided that the easiest way for me to be fair to all is to flat-out decline everybody, even the Dalai Lama.
If you work hard at the craft, like all the rest of us wordsmiths, something may come of your gift, may leap out of the sea of your heart like a dolphin and make a huge splash.
And I wish for you a big fat bestseller---even with that terrific idea that I didn't write for you for the 50-50 cut.