By seeking approval from others, you are placing a burden on them. People feel that when dealing with you. That burden weighs on their unconsciousness, which makes them less confident about you.
Place that burden on your own shoulders. Focus on the work. Do not distract yourself by shifting the burden off of your shoulders by offering yourself explanations. Accept that there are things that are beyound your control, and don't let them drain your energy.
Before others have confidence in you, you have to have that confidence in yourself first.