I agree with heaven, fake it until you can do it without thinking... I'm like you - shy to the point of frustration. Plus I'm hopeless at small talk - but I keep trying. Small baby steps lead to giant leaps. For me, I'd just try turning up, then when i was comfortable with that, I'd talk to a few people, then I built up the courage to say "Hello" when i walked into a room full of people. Now I can say "Hello" and i don't mind too much if no one says Hello back.

It's a skill you need to practice - try talking to the checkout operators at the supermarket (hello, how are you, how has your day been? isn't the weather warm/cold/freezing, wish it was summer/winter/spring etc - well that's how I started.