"You can please some of the people, some of the time,
but you can't please all of the people, all of the time,
so you may as well do what makes you happy"

Take it from me. I've been on the receiving end of a whole spectrum of correspondence and feedback about what I do. It ranges from very encouraging and positive to highly-critical. All of it is good and you just need to remember that any feedback you get is just someone's point of view. They're entitled to it and you are entitled to disregard it if it makes little sense to you.

If you plan to be a creative person, you will need to be prepared to stand up for your work, and to believe in yourself. Accepting that not everyone is going to like what you do and that someone else's opinion is just that: an opinion and nothing more will help you a lot.

My thoughts about creative confidence come down to these points:

Don't pander to what you think others may like, because you will only get lost as you are torn between one opinion and another.
Following trends only means you are conforming. You may be fitting in, but you won't be standing out either. Creative confidence is all about being an individual and finding your own path.
Don't create your photography looking for kudos, because you will only get lost as you seek others approval. See point 2.
Remember to enjoy what you do, because that joy is a sign that you have tapped into the right kind of creative direction: if it feels good, then you've found your creative-flow and you should run with it and see where it takes you.
Don't be overly critical of yourself because a serious case of 'writers-block' will only ensue. Instead, try to remain grounded and seek honesty with your efforts. All artists create bad work and what separates a good artist from a poor one is the ability to be objective: they aren't scared to see what they've created for what it is, and to work towards excellence in what they do.
Celebrate it when you create something outside your usual parameters; it is surely a sign that you are experimenting or reaching new ground in your own development.
Accept that nothing is a failure: bad photos, images that didn't quite work out teach us so much and besides, art should never be judged as successful or unsuccessful: it just is what it is. We are not here to give marks, to score points. We're here to be expressive.
Above all else: try to trust yourself and your judgement. Take note of when you 'feel' something is right and wrong and act accordingly.

I think the last point is perhaps the biggest one for me: learning to trust yourself, your judgement and your abilities takes confidence. Confidence comes from really knowing yourself and knowing where you are with your art. Good artists are always asking themselves questions about themselves, they are always seeking to grow and are always open to the thought that their art may take them to places they had never imagined: if they are willing to let go of personality traits such as being overly-critical (never happy with what they've done), overly-controlling (expecting a particular outcome), too easily pleased (happy with the usual), then some great art may come their way.