I don't think I know a single writer that hasn't been through a crisis of confidence at least once.
I found a load of great advice in "Show Your Work: 10 Ways to Share Your Creativity and Get Discovered," by Austin Kleon. I'm sure a lot of what Kleon has to say comes from common sense, but he's a man after my own heart when he says "Follow me back?" is the saddest question on the Internet.
It was the advent of social media that made my blog even possible—prior to that, it was just sending an annual email out to friends, telling them what I read that year (which I still do—old habits die hard.) But I've never been comfortable with pimping my work on the Interwebs. If someone thinks I have some good things to say about books, and ... you can read the rest of the review here.