Help. My Fermentation Ceased Early.

I'm new to home brewing, so I bought one of the standard beer kits and was doing my first batch (a Belgian Trippel). After the first 24 hours it bubbled very little and then stopped entirely. I noticed that the temperature of the beer was about 79 degrees at the time, so I moved it into my basement where overnight it reached about 59 degrees. Did I kill the yeast, or put it into some sort of hibernation it can come back from? I opened the primary fermentation and stirred with a sterilized spoon to try and get the yeast back in suspension, but didn't notice any bubbling yet? If I've killed the yeast, is there a way to save the batch? Add more yeast? Accept it as it is? The alcohol content was supposed to be around 9%, and mine is currently at about 5.5%. I wanted to let it actually ferment before moving it to the secondary fermentation, and then ultimately bottling.


Thanks in advance for any advice.

are you at final gravity?  at what temp did you pitch the yeast at?  How are you calculating ABV?  What yeast did you use?  The only way to know for sure if the fermentation is done is to take gravity readings.  If it is the same a couple of days apart you are done.