Welcome SS. This forum is so helpful.
I was in the same boat as you for a couple of years before I joined. But now that I have, it has completely changed the way I'm approaching my commitment to sobriety.
I'm sorry to hear about your mother. Alcohol seems to have a clever way of tricking us into believing it's not the problem, no matter how much it hurts us or how much we have seen it hurt others.
It sounds like being there for your son as he grows into a young man is very important to you, and that you believe saying no to alcohol for good will ensure that. This is as good a reason as any. I think if you keep your mind focused on that, you'll be able to flick any urge to drink away like a pesky mosquito.
Stay strong and focus on what's good in your life right now. And when in doubt, come here for support. One thing that I learned from joining SR is that I am never alone!