i was having the same elbow problem a week ago. here's how i solved it.

i usually sit when i practice guitar cause its more comfortable and with my alder guitar its heavy and stuff. so when i would sit down and play, i would anchor my elbow somewhere on the guitar and start playing with the elbow anchored, and that makes me move the elbow around instead of my wrist. i kept trying to use my wrist but i just couldnt.

so then i decided since i just learned star spangled banner hendrix style, i should stand up and see if i can play it. now, i got so used to sitting down that when i stood up i couldnt get my hand to move right. i kept hitting the wrong strings. so then i decided to keep my hand off of the guitar at all times and just move my wrist around and it worked. and those elbow pains went away.

now when i sit down im used to using my wrist it comes natural and i dont have to worry about tendinitis (tennis elbow).





but i dont know if you play standing up or sitting down so im not sure if this will work for you.