At this point, it's safe to say that your wine has too much hydrogen sulfide (H2S). Now you need to wiegh your options and decide what to do next.
I'd try aggressive aeration. Take a sample of the wine and go mental on it. Shake it, spin it, stir it, then give it to someone else
to smell it. If they say it's alright, then you know what to do with the rest of the wine. If not, continune
Get a copper pipe/tube and use it to stir the wine for 5-10 minutse. Let it sit for some time and then take a sample and ask someone else
to smell it. If everything is okay, the congrats. If not, continue
You can use Bocksin (or Böcksin)
, which will react with the H2S and reduce the rotten eggs smell. Rack after using it and ask someone else to smell. If the smell presists, continue
At this point I don't recommend going any further. You can
use copper sulphate but I highly advise against it.
It's very likely to end up with a toxic solution that might injure the drinkers and/or even kill them. I say just let it go.
Next time make sure you sanatize properly, use the right amount of Campdene tablets, and add enough yeast nutrients.