I have better luck playing cards on the computer - holding them in my hands even now at a mild stage really bothers me.

Sometimes if I'm doing certain things - I will get a little ache in my elbow- but then I stop if I can and it will fade away.

But I never have gotten the bad burning like you describe. It could be you were causing more irritation or compression to the nerve while playing cards- posture/arm/hand positions??
Did your arms get fatigued or heavy feeling also? That could indicate more of a vascular compression.

There is the delayed pain reaction with TOS also - that's why you are more sore today.

Has the color returned to normal yet?
Any swelling?

Oh and have you read about RSD? {we have a forum her for it too}