Wrist Hyper extension injury

Hi first time here, hoping you can help. 3 months ago i injured my wrist playing tennis, i was not looking ahead when my opponent hit quite a hard ball towards me in the 5 min warm up period, i didn't see the on coming ball till the very last second , i tried to react quickly & return the ball, unfortunately i didn't have time to lock my wrist when i hit the ball. My wrist bent along way back, i felt a popping sensation in my wrist, with slight pain, but was able to continue on to finish the match..The following 2 months, on the back of my hand near the thumb & next finger down to my wrist joint would often randomly have excruciating cramping pain. I still have aching & swelling around the wrist area below my thumb, trying to move my thumb is still sore. I went to see a physio last week, he advised i do hourly gentle thumb stretching, wrist extensor & wrist flexor stretches, also neck stretches. Is there anything more you would recommend to speed up my recovery? I am a tennis coach & hoping for a full recovery. Thanks in advance.

Have you had an X-ray to rule out a scaphoid fracture? Once excluded I would progress treatment then.

Thanks for your reply, yes I'm sorry i forgot to mention that i had x- ray's taken 2 weeks ago, for scaphoid etc. results came back normal. I only started my stretching program 3 days ago, will i feel a difference in strength after a week or 2?? Also would you suggest that i have a cortisone injection to speed up the healing process? As inflammation showed up in the recent scan results. Thanks in advance..