Hi Izzy,
I recently discovered a section in SR called secular recovery (I think) and it has some very interesting and helpful information about the science of addiction.
I'd keep it very simpy with young kids. With my 19 year old son? Our conversations are very frank and honest, which is just the way I want them -- and it sounds like you do, too, when the time is right. He and his friends are equally honest about this stuff -- they spend enough time here to know I sit in my "spot" with a glass of wine more often than not when they pop over in the evening. Several of his buddies have recovering alcoholic parents that I even know of. They like me anyway, I make them dinner and keep up with their lives. I:-). I know my son doesn't drink (a weird positive impact of parents who drink) and his friends don't drink when they are here at least.
It will be OK. Your kids love you and will forgive you and learn empathy from this.
Have a happy Easter... My potato salad is made for our dinner at my niece's house -- yeah! Why do I volunteer for such a labor intensive side dishes, lol?