It is always the best to socialise with people. Living in solitude will only let that negative energy manifest and grow stronger sometimes controlling and dictating your actions.
To be confident, as you stated it starts with changing the way you act yourself and no other factor can have such a toll on your confidence except for the fact you limit yourself.
Really interesting post @jonathanyoung
thank you for your well thought out comment as always @arkrai. I totally agree!