As well as golf I also rock climb, and naturally put an awful lot of strain through my fingers, elbows, and shoulders, and in the past I have suffered from both tennis and golfers elbow, but no more. With golfers/tennis elbow you have placed a lot of strain through your wrists, elbows, and shoulders and you are reacting to it, and this is simply because your muscles work in pairs but that’s not how you are exercising. You need to work on the antagonistic exercises to work the opposite muscles to the ones you are naturally strengthening. In a lot of people this is found in the shoulders and triceps, hence why most pros now also hit the gym.
in order to start to cure the problem start to gently stretch out the tendon, and as mentioned the theraband flex bar is a great way of doing this…as the pain decreases you then need to start to build the supporting muscles, again a good way to start are narrow press ups where your elbows touch your sides as you push…. But the most important thing is that when the pain has gone you have to continue the exercises otherwise the problem will come back..
It is a degenerative issue, don’t look for the short term fix like the elbow straps, they may make the elbow feel better, but the damage will be getting worse