I agree with Ian.
Also- you didn't say, if your elbow swelled or colored. If it hurts only on a specific range of motion or all the time, even while resting. All this makes a difference if you have an inflammation or stretched/ crushed something.
I suggest rest, and if you train tell your sensei about it so he and all the others will go easy on that hand. When at home or just working (don't know what you do) try to keep the elbow warm by wrapping it in a scarf or something. Did you rub anything on it like Ben- Gay, Tiger Balm? though they are better for muscles and you seem to be talking of more boney parts (though you didn't specify).
It's your life and health, and I don't know the rules in your country but it's a big risk doing MA's with no health insurance.
Take care of yourself and be careful.