As someone who also posts in Clye I understand your sensitivity. A number of years ago I had a treadmill "accident" which the whole gym heard and saw. Haven't been on a treadmill since!

First all, hope you are OK. Sounds like you got seriously hurt so take it easy. Second, that woman was interesting that she had the lack of tack to ask you about your back. I can only hope she was geniunely concerned and wanted to start a conversation with you (although tacky). And don't let your pride keep you returning to spin. I have often been the biggest person in class but I am far from the weakest (and am in fact one of the strongest) and like to show those young skinny things that being big doesn't mean you aren't physically fit. Get back in there and show them you can ride most of their skinny little lycra covered butts off!

take care...