As for me, I cut my hair really short to feel better. About everything, basically. Some people go shopping to destress, but I cut my hair when I feel down. It's obvious I rarely feel disappointed with myself because I used to have long hair before chopping them off. Little change(s) you make to yourself can help boost your confidence. What's your booster?
p/s: The feeling of being a new person is always the best. It's like you've started with a new canvas to draw your paths of life.