Ugh, I empathise with how hard it is to go up to a groups of friends. I could never do that. I was lucky in my case since I pushed myself hard to be proactive at the very beginning when no one knew each other, and managed to form a 'safe' group which grew enormously, something I actually didn't even want. Is there anybody that strikes you as non judgemental and friendly, more quiet, or maybe someone who is also on their own, or in a pair rather than a massive group? I would stick to those who may appear to be more likely to want to make a friend or so.