You can't overcome shyness.
It's best to accept it as it is and move on from there.
If you spend your time looking for faults in yourself, you're introverted, ignoring the rest of the people on this planet.
It'd be best for you, as it is for everyone else, to get out there and mix with others.
Nobody else's perfect, you know.
Mixing with them will help you realise you're not so terrible a person after all.
Narcissism is far, far more a problem than shyness.
And it's not the only one.