If you attempt to squeeze the bottle if it is hard, then you likely have continued ferment ( and you likely have continued ferment). Typically 2/3 of the ferment is completed by Day 8 and some ferments can take months to finish up. A month is usually a safe mark to check and see if dry.
If you saw fuzz, you saw mold...white is classic with what you made and circumstances.
SO2 is sulphur dioxide, achieved by adding Campden tabs or potassium metabisulphite to your must/wine at indicated times....used to maintain a safe environment for your yeast, for your fruit, for your wine. Classified as a preservative http://vinoenology.com/calculators/SO2-addition/
May want to do some reading about winemaking, this is a great site .. http://winemaking.jackkeller.net/
My suggestions...important: buy potassium based Campden tabs that are dosed at one tab per gallon or potassium metabisulphite, aka k-meta. Avoid the sodium versions, because they are, well, sodium based...but you can use them interchangeably. To your 2 L add 1/2 a crushed campden tab that was dissolved in cool water. Remove all pulp pieces, place under airlock, and in a month, if there is a layer of sediment then rack the wine. You could continue to rack, read Keller info, stabilize, bulk age, bottle, etc. Oh, and invest in glass or Better Bottle type PET bottles....this is a 2 L batch, and you could easily transfer to a 1.5L wine bottle and a 0.5L and airlock them. Use balloons if necessary, some people use condoms since they are sanitized already. Avoid the obvious, powder or lube. If you continue with gallon batches, use a glass gallon jug, know friends who drink jug wine?, find a 2 gal food grade bucket or 2 gal glass cookie jar....your primary. This way you will get 4-5 750ml bottles per gallon. Most grocery stores get their cake frosting in 2 gal buckets. If you want to know where your wine is..grab a triple scale hydrometer ($3-10).
Most realistic case...dose with Campden, keep in refrig, drink soon. Try again with knowledge.