I decided to quit for many of the same reasons. I have two small kiddos and one on the way. I wasn't drunk all the time but I sure was drunk A LOT. I would imagine I've been drunk at each of their birthday parties. I haven't been a bad dad... but I sure could have been better. And I have to admit... most of the mistakes I made as a father, in reflection, were because of alcohol. And if not the alcohol - the regret from drinking.
I also started having panic attacks from those awful hangovers. Feeling like death, like I might die, like I could pass out or have a seizure at a stop light when boxed in by other cars. Heart attack symptoms. Heartburn. Awful, awful digestive irregularity. All because of drinking.
When you spend the time sober and reflect on how much life improves sober vs. how incredibly awful it is in the cycle of drunk/hungover... it seems insane to live any other way than sober.
I started this quest for the same reasons you have. I was becoming more and more like you described your mom. If I stop now I will avoid that cycle. My kids are young enough they won't remember the countless beers and bottles of wine. They will know a sober, involved dad... who doesn't feel like he might pass out from panic attacks at stoplights. =)
Stay strong.