Throbbing like a sick dog's ass

self inflicted significant pain

I wrecked my motorcycle and now my foot is "throbbing like a sick dog's ass"

Throbbing like a Sick dog's ass

Intense pain, usually of a self inflicted variety

Damn, I wrecked my motorcycle and now my foot is throbbing like a sick dog's ass

Sick as two dogs

When you're not just sick as a dog- you're sick as two dogs.

I'm sick as a dog. No, scratch that. I'm sick as TWO dogs.