Self anger leads to bad choices

I've never been one to hurt myself on purpose, at least not really. But recently, in the last six to nine months, I find myself wanting to do harm when I mess something up, like my relationship or friendships or something with my college kid. I know I will never do the extreme, but I've been hitting myself as a form of punishment for stupid behavior or messing things up. That's not good at all, and I would love to hear some other coping mechanisms or avoidance mechanisms. It's been getting a little better this month but the desire is still strong. Any advice?