I'm wondering if you have been checked for carpal tunnel syndrome? I had similar symptoms with the worst pain at night. I wore a splint at night that helped. I had carpal tunnel release surgery done on my left hand 7 years ago with great success in relieving my symptoms. 4 weeks ago I had the same surgery carried out on my right hand because I developed the same problem with my right hand. It appears to have been very successful as I am no longer experiencing any pain just a little residual tingling and numbness in my index finger that I expect to eventually disappear. Worth asking your doctor about nerve conduction test n your hand.