“From my close observation of writers… they fall into two groups: 1) those who bleed copiously and visibly at any bad review, and 2) those who bleed copiously and secretly at any bad review.” 
― Isaac Asimov

In my opinion, one of the great mysteries of life is how to handle a bad review.  I’ve heard it all: we should use bad reviews constructively to improve our writing, we should ignore bad reviews, we should embrace bad reviews, blah, blah, blah…

The simple truth is, bad reviews hurt.  You’ve spent months, even years, turning the thoughts in your mind into a story.  Hopefully, it’s a story that you like (if not, you should consider who it really is that you’re writing for) and you put it out there, hoping that everyone else likes your creation.  You devour the good reviews like a jumbo sized bag of M&Ms.  They feed your ego.  You begin to believe that you’re the next Hemingway.  Then one bad review, stops the train with a screeching halt.  Like a cow stuck in the middle of the tracks, you can’t get past it.  Why didn’t they like it?  Why didn’t they like me?

The best advice I can give is, LET IT GO.  Crumple it up in your head like a piece of paper and throw it in the virtual trash.  Remind yourself why you write and for whom you write.  Think about books that you didn’t like and how quickly you moved on from reading a bad book.  As a writer, if you must read the bad reviews, read them and then just move on.  You can’t please everyone, any more than everyone can please you.

That having been said, bad reviews still hurt.  The negativity of one has the power to wipe every good review right from your memory.  So I’ve developed a strategy.  I have my husband read the reviews.  If it’s a bad one, he says things like “They don’t know what they’re talking about” or “They weren’t even constructive, they’re just being mean.”  You always need a loyal friend in your corner to soothe the hurt, to protect you from the barbs.  I allow myself a few minutes of self-pity, then I turn back to my computer and keep on writing.