I was at Lydd and heard you on the radio that day. You did the right thing and asked for advice. Your checkout sounds a little rushed and it may have contributed to the problem somewhere (I don't know how, but the CFI didn't find it did he?).
Personally I would chalk all that down to experience and spend a little more time gathering knowledge before contemplating running a group. You will find some in the group will be co-operative and others will not. Why not join a group and gain experience before committing? Lydd manage several groups - come down and have a chat about the details before contemplating trying to run one.