blow off steam

Maybe you're angry for some *waves hands* reason, and need to blow off steam with some shoot-'em-up action or dissociate from your everyday reality.

“If Tommy wanted to hit for 15 minutes to build some confidence, blow off steam or take a break from his homework, he could just go outside and do it,” John said.

“It’s where I manage to earn my livelihood, and I can show people my joy and blow off steam, you understand? It’s where I feel happy, good.”

Some people blow off steam by yelling at their television screens.

“He would say things similar to that on occasions to blow off steam. But I wouldn’t take them literally every time he did it.”