CTS after wrist fracture

I had a fall and fractured my distal radius nine weeks ago. Non-displaced fracture - plaster cast four weeks then as advised I wore a splint at night for the first week. The following week I woke with numbness in middle two fingers and since then the CTS symptoms have steadily worsened with pain and more widespread nighttime numbness despite wearing a splint. (I'm 62 and had some osteoarthritis in hands and wrists before the injury but that is apparently not very serious. I do have noticeable atrophy of my thumb muscle and lots of tenderness in the base of thumb joint since the injury). Now I'm finding that if I do very little with my right hand the symptoms reduce, but my wrist is so weak I'm trying to build up strength. I love swimming but that really worsens the CTS. I looked up exercises as I'm really keen on self help for my own health - anyone had a similar experience who could give me some encouragement?!