Welcome, Sadkitty - I've been to many MDAO (and other) support groups - nothing to worry about!
First of, at the beginning, people give their names (or names they would like to use that day), any condition they have, and if they'd like to talk or not. Not everyone chooses to talk.
At MDAO, the rooms are smallish, and there are usually 15ish people. When people are sitting, waiting for the group to start, the atmosphere ISN'T so tense, partly because some people know each other.
What a great feeling to find out that someone does/thinks the same (negative?) thing that you do!
Please let me know if you have other questions!
Peter