Could be a bit of Repeatitive Strain Injury. (RSI)
I suffer this in my left elbow and wrist sometimes.
Have broken the wrist twice, and the elbow pain is down to playing guitar and lifting weights

Elbows that are sore can be really uncomfy when riding, and can take a long time to settle. Sometimes my arm can just feel heavy & numb, this is a side effect of RSI. I think some support like a bandage or something would help It's worth a try anyway!

I took a while out from riding & just made an effort not to use the arm to do strenious things for a while (not like opening a jar is normally strenuous lol, but it hurts when you have sore joints!)

Hope you dont have to get an nasty injections and that yor arm get better soon!