I feel you, I am painfully shy myself. I thought I would open up more in sl, but I'm still me at core.
I agree with the above. Work on your avie, make it who you want to be and make or have made some nice pics. The most common things people start a conversation with me about is my pics and the work I put in my avie. Seems like vanity, but it isn't, I look at as appreciation and the reward is the other person helping me bust through the shyness.
Best of luck.
(edited cause I can't type on my gosh darned phone at work! )