Realize that other people have their own issues. Sometimes you may feel that other people are standing in your way, causing you to feel "less" of a person or to put down your own endeavors. Criticism is commonplace from others but not all of it is constructive or from a place of true concern for your well-being. Learn to sort between the unhelpful barbs that seek to prevent you from reaching your full potential and the feedback that is actually aimed at helping you to grow in the right direction. It can take a little time to sort this out but it is worth it and you'll know in your gut what is sound advice and what is simply obstructive. Remember that many people are carrying their own confidence concerns and some of them are insecure enough to try and pass their worries on to you too.