All I can say is JUST forget what others might think you are the one that matters, if you get your heart rate up in a safe way then who cares what you look like just enjoy the music and the moves will come
STOP thinking too just do and not try. Sub concious or routines where u do not think use quicker neuropathways hence you respond on time, takes longer to think about a move let it become habbit.
Try a differnt instructor maybe the one you use does not que effectivly for you and another instructor may que differently. Just a thought
Ps i teach loads of aerobics and still go wrong lol hence i am human and people like that, BTS trains people not roberts yeah i feel silly but hey laughing is great for the abs