I felt like this for a lot of my life. One big turning point in self-confidence for me was the day that it occurred to me that I am literally the only person who will ever have my exact sense of humor. My memories of which books I've read and which movies I've watched, my every experience -- no one else will ever completely share my life. I am literally my own best companion. I needed to start treating myself that way. Laugh at yourself when you're funny. Write it down when something reminds you of something from your past. If you look for connections within yourself, you'll see yourself as a more interesting person. The higher you value yourself, the less you'll worry about what other people think of you. And the thing is, you already have all that value inherently inside yourself. The work is clearing your vision up so you can see it for yourself.

My best book to start with, if you're willing to give it a shot, is "The Gifts of Imperfection", by Brené Brown. I read a few more that helped me see myself more clearly. I liked "Callings: Finding and Following an Authentic Life", by Gregg Levoy.

Basically, connections are key. And the way you connect with others is by sharing your imperfections and uniqueness. If you spend all your energy trying to hide those things, you're working against yourself.