You have tennis elbow, i had it and it took a complete long year to completely recover, and it didnt recover by itself i had to work hard for it, this is my experience
- If pain is too much try to stop for a couple of weeks, it wont solve it but you wont make it worse. If you do this chronic get ready for a full life of pain, and not be able to hold any weight in the future, grab anything without pain, etc When pain is a little less start doing the next points, its better to stop 2 weeks and then start riding with the neoprene cover
- If your bar pressure in your kite is too heavy, change your kites
- Ride with one of this neoprene protectors, it will help you to not use that much your elbow when kiting
I used one when i rided and it helps to not make the pain worse.
- Ride with your thumb finger over the bar and not under it
- Make small pauses in your sessions every 45 minutes or so, do not hold the bar for too long as this sustained position is what caused you the pain. stretch after your session and then use ice
- Physioterapist work, i had around 40 sessions, works
- stretch the elbow before and after kiting. I did all day too and this is what ultimately helped to heal it. Search for stretching exercises in the net if you dont know how to. When i mean all day, i mean it, i could stretch it maybe 50 times a day
- Once pain is almost nothing, start with exercises to make your forearms stronger, i had one of this grips and i used it 4-5 times a day, usually while driving
Do not take this lightly, i have friends with this chronic pain and believe me its not funny, its not about kiting or not, your whole life will be affected. I had to do all of the above for 1 year in order to heal it