Group conversations are hard as hell for me as well. I know what I’m supposed to do, but it’s hard, so I often am quiet. Generally what gets me anywhere is if I really plan out something I will say. I hear someone say something and try to think of a response that is very quick and to the point. I know that if I have a thought that takes more than a second or two to say, I might stutter or get too anxious to explain myself clearly. Plus, in groups, as you mentioned, people can talk at a faster pace. If they lose interest or don’t know what you’re talking about, they’ll often change topics and move on instead of trying to ask ‘what do you mean?’, because people can be hopping from different people/conversations. If someone wants to hear something longer from me, it’ll usually be pretty obvious and prompted with questions, and patience with me stuttering at all. But I assume that is not the case normally. It’s frustrating but i don’t take it too personally because it is just a skill to develop. How I would talk comfortably in a 1on1 situation just isn’t the same as in a group.