10 years later is not thee reason your wife is an alcoholic. Just as it was your choice to enter into an inappropriate relationship it was her choice to pick up the bottle to deal with it.
You asked how long should it take for her to forgive you - I am no expert. In my experience of couples that have dealt with the same it has taken around 2 - 3 years to recover from an affair. Not sure if the forgiveness part took that long the regaining trust part did. And have known couples that could not forgive and split. If you can't forgive your spouse for something and are going to hold on to hatred then there is no point to stay together.
Whether that ^^^is what's going on I don't know. What I do know is your wife has used your affair for 10 years as an excuse for her own poor behavior. That's a pretty extreme case of blame shifting.
Sorry you are here but glad you came. I also hope you will start with Al Anon it will help you get through this.