You can never boost your confidence if you are surrounding yourself with people who bring you down. Those kind of people are negative and you do not need them in your life. If you have a friend who is constantly making snarky remarks or have a co-worker who goes out of their way to make you feel bad about yourself, try to distance yourself from them. You need to replace them with friends who make you feel like you are the best version of you that you can be.
In the wise words of Hannah Montana, “everybody makes mistakes.” You are not a superhero and you are not perfect (sorry to break it to you). That being said, you need to accept your mistakes and learn to not make them again. Mistakes really have an impact on our confidence and can make us feel like we aren’t good at anything. You will, on average, make one small mistake a day. When you accept those mistakes instead of dwelling on them, you will regain that little boost of confidence you loose every time you freak out over a mistake.