I got 'tennis elbow' from repeatedly pulling out a heavy lower drawer on my desk at work. It was aggravated by lugging heavy luggage around when traveling (this was before all suitcases had wheels).
I had to stop doing the repeated motions -- moved things to another drawer -- got suitcase with wheels. And, I had a strap to wear on my lower arm, just below the elbow. Mostly, the strap reminded me to avoid the motions that would re-aggravate the injury!
You should try to think about the repetitive motions you've used -- what is most like a tennis arm swing, especially underhand -- and arrange your work so that you don't do that anymore.