sidony, I'm so sorry group is so hard for you. Do you think they were attacking you because they sense you are not being honest with them? What would happen if you told them what you just told us? How frightened you are to talk to a group of people, how your mind goes blank, and how you believe you would look like a fool if you tried to talk and they would judge you? Then at least they would know the truth and maybe might even be more sympathetic or helpful to you.
It is interesting that it is easier for you to continue with this seemingly miserable experience each week than to terminate it. (Kind of like me and my marriage!

)
Hang in there.
sunny