Gibson,
There is nothing wrong with quitting for your family, and if that keeps you motivated, use it. Some people give up their lives for their family, so there is nothing wrong with giving up alcohol for your family. If someone won't sacrifice for their family, who are they supposed to sacrifice for?
I know it seems like a lot now, but if you hang in there, one day giving up the drink won't feel like a sacrifice at all, though, and you will be surprised at how much easier things are when you aren't constantly being dragged down by alcohol.