umm... how the hell did you manage that? lol. next time only press the format sd button, not format system
as far as fixing it, thank god you still have cwm. as far as the computer not picking up the sd, did you go into mounts and storage and hit the bottom option "mount usb storage"? because that should allow it to be read like a flash drive, other than that youll have to try to force something onto the sd through the computer directly using a card reader, and the problem might actually just be the sd card itself, if it was improperly formatted it can in fact crash the os itself, try booting up without the sd in there, and if you cant mount that card in cwm the way i described, try a different card