Suggest Treatment For Swelling And Pain In Elbow

I have a history of tennis elbow on my right arm, but recently having severe pain on my left elbow joint, it is swollen and I am having trouble even lifting a cup of juice or gripping a plug to pull it out. Could this be tennis elbow too? I did knock it quite hard a couple days ago, but there was no bruising, so I dont think this can be it.