I haven't read your book yet but it's in my queue. Like I said in another forum, one bad review doesn't define us as writers. Even if the novel doesn't thrill the public and never sells (neither of mine are selling substantially yet), if you love writing, then just write another.

My source tends to take over when I write, but I don't think that was true when I started writing about 50 years ago (yes, literally). These days, my source becomes the characters I write about, who take over the plot. Sometimes they piss me off, because I don't have the final say on their fate!

I'm sure you've heard it a million times, but just keep writing. No matter how good it is (or bad, and sometimes it will be bad, at least to some people), it will improve, hopefully to the point where something sells like crazy.