I've never been to a retreat, but I'm like you in that give a presentation-piece of cake, go into a room and introduce myself in a social situation and I feel sick. I plucked up the courage to join a quilting group and the ladies couldn't have been more welcoming and friendly, and after the first terrifying moment of walking in I now eagerly look forward to going and cant wait for my monday quiltin group to come around. Go relax and enjoy