As many mention here, the best is to find a doctor focus on sport rehab and somebody that make sports. So he understand why you one keep doing this even this caused painful on your ankle. After 2 year with pain similar Achilles tendinitis in both ankles i learn to live with this but find the way to minimize and share with my day to day activities.
I used this ankle sleeve this in particularly have a internal reinforce to the ankle, are very comfortable and you can surf without any problems. This sleeve even in hard conditions never move and keep in position.
Used this is the only wave i can surf or ride hard battle on MTB, this minimize the pain but not make go but at least let you do the sport that you like. After that just put some ice and relax and stretch a lot for the tendon keep elastic

sheers