Well, my friend, I've had bruising like that too from a really bad muscle spasm--but it only happened twice ever for me. That was back in 2003 when I was getting spasms where it felt like the muscle was ripping off the bone.

I feel for ya.
And WHO told you you were working to much and had to be careful?????
Warm, damp compress would be good. Have you considered an epsom salt bath?
Hope you get some relief.