Overcomming Self consciousness

I'm a pretty shy person and i have diffuculty with overwhelming self consciusness in life but when i'm acting it's gone whether it be as a character or myself.

Anyway I'm after any advice for tackling this problem, its not a good way to go through life , I feel as if i'm watching my self all the time without being in tune to whats around me. The more I act with my immagination the more it goes but it keeps comming back when i stop using it.

Thanks