Notes from a soft sniffer ...
Don't use one tablet per bottle - that's overkill and the sulphur smell will take ages to dissipate. Put two crushed tablets in a clean demijohn and pour the wine gently from your bottles into it. Give it a good long stir (not too vigorous) to dissolve the powder and seal the demijohn with a bung or an airlock - or even a cotton wool plug (if it's not staying in there for very long). That'll stop any further action in the wine.
The bottles can then be washed properly and, as they've allowed a mould to develop, sterilisation is the best course. You can do that with boiling water, something like Milton, or by using a strong metabisulphite solution (6 tablets in a couple of pints of cold water). When you've sterilised them (unless you used boiling water), give 'em a good rinse.
Now the big thing. Why are you bottling? If you don't need the demijohn for more wine, leave it in there and bottle a couple of weeks before you want to drink it. The wine will improve in the demijohn - it will hardly improve at all in a bottle. However, if you really need to bottle now, then make sure that not only the bottles but also the stoppers are clean (you can use the same methods on those). If you're using natural cork, in fact, you're best boiling them for a couple of minutes - natural cork is slightly notorious for carrying infections. From the looks of your photo, the infection may very well have come from the stopper. And make sure that your air-gap isn't too big - about a half-inch is right, and three quarters of an inch is maximum.
Enjoy it when you get round to the guzzling stage
Mike