What you're smelling might also be what we might call a "green beer" smell. Once the yeast have chewed through all of the easily reachable sugars, they will work on "cleaning up" after themselves by getting rid of acetaldehyde, a by-product of fermentation which can have both the smell and taste of green apples. Get thee some patience, grasshoppah! Yes, some beers can be "done" in 12 days, but yours obviously needs some more time. Leave it completely alone for at least another 5 days. Better yet, start another batch to take your mind off the first one!