People grow apart sometimes. Again, I don't think the drinking is the big issue here. It sounds more like two people who, for whatever reason, have grown apart but it wasn't really addressed until your husband got the DUI. Since then, you have been unhappy with the way he handled that, and continue to realize how many annoying habits he has and opened your eyes to the way he pretty much disrespects you. I doubt all that just started when the got the DUI, it's just that the DUI caused you to really look at things and realize how unhappy you have been for a long time. It gives you something to point to.
I agree that it seems like you both want the other one to be someone you just aren't. Perhaps it didn't really capture your attention until the DUI incident, but now it has and you can't put the cats back in the sack.
I also agree that if you cannot accept each other just as you both are right now, someone has to make a decision to split the sheets. I have had a feeling that you are afraid you will lose a certain lifestyle if you separate and that is probably true. You have to decide which is more important...your serenity and peace of mind, or your Lexus, big house, not having to work, being able to home school your son, vacations to exotic places, etc.