I went to one this past year at school, for general anxieties. I didn't speak for the first two weeks, but eventually it got easier to speak. We had to do a check in each time, and mine was usually a sentence or two, but by the end I made a full paragraph and even spoke up by myself (after a lot of rehearsing and false starts). But people really listened to me, and I liked it. They paid attention to what I had to say, because I didn't speak much- and they told me that at the end. Even if you dont speak right away, its nice to know that other people get the same physical feelings and thoughts running through their minds. Or you can just nod if it applies to you. Thats what I did a lot.
Valerie