Okay, you'll need to add about 50 PPM FSO2 to knock it down. Being as it's a couple of months past pitching and still throwing bubbles, that's probably a wild lactic acid fermentation. If you bottle it like that, it will probably leak past the corks and might blow up the bottles.
Campden tablets are 19th-century junk. Throw them out and buy some potassium metabisulfite powder. Get an accurate teaspoon measure and dissolve a half teaspoon (or three grams if you have a really good scale) of sulfite in a half cup of cool water and stir that in gently and thoroughly into the wine before bottling.