When things go wrong...?

[the possum]

I've got some apple wine brewing in the garage now, and I'm starting to notice off aromas from one of the jugs, when earlier it smelled like apples and fresh bread.
I still have no idea what I'm doing wrong, as I sterilized and scrubbed everything with a big bottle brush, and sterilized the must with Sodium Metabisulfite. I think I'm just gonna get some Campden tablets so I can't screw up the dosage rate...

But anyway, my real question is, what do I do at this point? Is there anything that can be done to salvage it? Would racking it off the lees help? (there's not much settled at the bottom anyway as it's still brewing pretty good) Maybe give it to a hillbilly to distill into something drinkable? I realize it would have been better to prevent this in the first place, and I'm gonna make some changes before my next batch. But any insight you guys could offer would be appreciated.