Try this exercise it worked for me.
https://m.youtube.com/watch?v=we4UoiKG3Co
For the past 4 months I have had a sore elbow joint and it extends down the forearm muscles and up between the Bicep and Tricep which I think is called the Brachialis. Painful to get lids off jars and grip etc.
Thanks for that link, basically he suggestes massaging the area for 1-3 minutes and then very light resistance exercises.
I do feel about 20% relief from my first go at the exercises.
How long did it take you to cure the problem?
I assume these exercises are to be done once daily.
He said the muscles need to be strengthened, did you find the very light resistance exercises enough of did you use a bar and add weight?