I bite my nails, have repetitive/racing thoughts, get paranoid, and try my best to avoid drinking. If a drop of whiskey hits my lips, it might be game over. Under extreme stress I'm apt to get completely shit face wasted and be a humongous asshole. It's had a bad effect on relationships to say the least.
A big yoga session, run, or meditation has an amazing effect on my stress. They can cause a complete 180 in my attitude within an hour or two. Also, addressing the source of stress works wonders. I make a list of everything I need to do and start with the easy stuff. helps heaps