First of all, may I point out that a critical review is better than none at all. Way better, in fact. There are books that have risen from obscurity to notoriety simply because of critical reviews. On a lesser scale, a critical review serves several functions, not the least of which is to cast a positive review in sharp focus by contrast.
But there are other benefits as well. For the purist, one may learn from criticism. But there is a caveat here; one critique does not a rule make. I have had to learn not to overreact for or against each critical remark, and not change my writing to accommodate every well-phrased zinger. Chaos that way lies!
So criticism, whether you agree or not, should be regarded as evidence that there is rich variety among readers, a thought that should always be present in the author’s mind. Not to try to write to each view, but to understand that one’s writing will not ever be universally applauded or accepted. The hope is it will be respected.
I am human; I prefer positive reviews. I like to be flattered. But I recognize that unflattering responses to my work are, in their way, tributes as well. Why? Because the reviewer was sufficiently charged emotionally by my work to bother to write anything at all. Is that not preferable to passivity? To nerves left untouched?
When my first novel was published, I eagerly counted Amazon stars, and delighted in each 5 star review (thanks, mom!). And then I heard a remark to the effect that a book with nothing but perfect reviews is viewed with suspicion, not idolized. To receive nothing but five-star evaluations is unnatural. It is inevitable in the natural course of things to receive a few unhappy comments, if only from a reader who misunderstood the genre or the nature of the work, who expected this but received that and was disappointed. It will happen.
How do I deal with critical reviews? In short, I don’t. I’m grateful that the reader felt my work important enough to take the time to respond to it. I look within the remarks for a useful tool for the future. And I move on.