Yeah, best advice I can give you is keep it in the carboy under airlock for at least a week or two. If it isnt visibly fermenting still, i.e. bubbles forming or that you can see rising, then check S.G. and stabalize.
No worries, all adding that sugar did was either a)ferment started again and youll have more alc. in this wine, or b) it didnt restart and you just backsweetened your first wine. lol So either a bit more stout, or just a bit more sweet is most likely the extent of damge and I wouldnt call either damage more like unplanned progress. If you havent smelled rotten eggs or anything in all this, id say you have a wine that is more than drinkable and may actually be very good. Just age it in carboy and let things settle, when you rack it off sediment taste it and if you like it and its cleared enough, drink away.