Fizzy Wine & Gravity Readings: Wine Wizard

QI have just made my first batch of wine, a white one. Funny things have been happening to it. Everything seemed to go well with the fermentation of the wine. When it was done, I transferred it to the carboy. As I expected, the wine cleared on its own. At this point I added a little bit of wine glucose to the carboy. After the wine cleared, I filtered it with a #2 filter and the wine was crystal clear. It looked really good and man was I excited. When I tasted it, it tasted fizzy like it had been carbonated. I left it to sit a little longer in the carboy, stirred it some more to possibly get any gases out of it and the wine went cloudy again. At this point I filtered it again with another #2 filter. The bottom of the carboy had lots of sediment. It was almost as if it was still fermenting or something but it had been in the carboy now for a month. Is this fizziness a normal occurrence in whites?