eat a bag - You say it when you're so angry that you could punch someone

You say it when you're so angry that you could punch someone and then eat a bag of dicks just to make it worse.

My boss said, 'Eat a bag!' when I showed up late for work again.

My friend said, 'Eat a bag!' when I broke his phone.

I said, 'Eat a bag!' when my crush asked me out and I was mad.