Deuce, stress is a part of life, concussed or not. Of course, reduce as many stressors as you can, but the stress that comes with every day activities is something you may not be able to control. When you feel it coming on, go off by yourself and do some slow, deep breathing exercises. This has been shown to reduce stress levels.
If you need to tell your boss, you need a minute, then do it.
As far as alcohol, they call it a "depressant" because it depresses the central nervous system and inhibits it's function. In doing so, both physical and psychological activities are impaired and reduce brain activity and awareness.
It blocks messages from the nerve receptors to the brain. My opinion, I don't need anything that messes my brain up any more than it already is! Ha!