My Manager is Completely inept. What can I do to keep my sanity ?

You are correct that you were on your own time, consuming an alcoholic beverage and in no shape to conduct business. I'd have a serious talk with your boss - and if something isn't done or doesn't change, take it higher. Why should you leave a job because of her incompetence. If you like the job than complain or see if you can transfer to another department (or if she can be moved). How long have you worked there, do you have an employment contract? Look at it and see what the terms are. Is the pay good, could you find a similar/better job relatively easily? Something to think about.