Unless I've missed something, shouldn't you be able to boot from your back-up drive again if you disconnect the main drive (and maybe the CDROM too)? You've already booted from it, and you didn't change the partitions on it since then.
Also, AFAIK a quick format only writes to a small number of blocks, so most of the data should still be intact on the main drive. The question though is whether the available recovery tools are able to find old partitions in these circumstances.
