How can one overcome Insecurity

You don't overcome insecurity.

You don't fight it. You don't beat it back. If you've tried, you've notice it just worsens the problem.

You either find out why you were wrong, and don't need to feel fear, or you dive in and endure inspite of your fears.

True confidence comes from being well practiced. Well practiced enough to know what's waiting for you on the other side. Well practiced enough to know that you can handle whatever is waiting for you.

Confidence is not the goal - competence is.

Don't try to run or push away your feelings of fear. There's good reason to be afraid - the world we live in is not always a hospitable one. You could really fuck up. You could really be hurt in ways in which you won't recover from. You can easily ruin or throw away your life.

Strive for competence. Acknowledge your fear; don't fight it. And one day you might just be surprised by how confident you have become.

Good luck.