Everything is exclusively in your thoughts. As long as you want to consider yourself a failure, you will. Each person, first of all, evaluates himself. If you give yourself a negative assessment, then it will manifest itself in life. After all, the people around you subtly feel you. If you think negatively, then convince them of this. Therefore, there is only one way out: take it and stop considering yourself a failure. The main thing is to start. Get up in front of the mirror more often and tell yourself your positive qualities. They are in any case. Remember more often positive situations where your positive qualities were revealed. Your task is to reconfigure yourself and convince that you are no longer a loser, but a happy confident person!
Nothing. You can't just take and stop who you were. You are hundreds, if not thousands of different algorithms of behavior.
Any problem is solved with the help of serious thoughts. You are looking for a problem, you find its source, you destroy it. Repeat the required number of times. Is it possible to consider the so-called character of a person and a skill, where, when repeating actions, the model is remembered? Xs, hardly.
Love yourself, first of all! A loser is the template that people hang up to themselves and get rid of it just as easily, hang a label with the words "I'm lucky in everything!")