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

 

oh yea, and just for the sake of covering all the bases though im sure you understood why i said to connect it to your computer, toss a different rom on there or a backup, either way will work, then install/recover it

 

You can copy files over from your computer using adb. See this post for more info

 

remove the sdcard, put it in your pc, copy rom to it, put it back in your phone, flash from cwm.

 

Sometimes it's the easiest options that we forget to think of. We tend to over think stuff sometimes.