Diagnosed With Severe Case Of Carpal Tunnel, Improved, Hand, Wrist, Forearm, Thumb, Fingers Goes Numb. Carpel Surgery Required?

I have been diagnosed with a severe case of carpal tunnel. My emg showed a 9+. Since I ve had the test, it seems that the carpel tunnel has improved. All this previous summer, though, I d wake up at night with my hand, wrist , forearm and my thumb and fingers numb. Also, when i ride a bike, my hand and fingers become very numb and hurt, just not the little finger. When I used the computer, I had severe tingling and numbness of the hand and fingers, but now, I just am having some numbness and tingling. Should I have carpel tunnel surgery or wait and see if it gets worse again. My doctor says that if I don t have the surgery, that I ll lose the function of that hand. Is that true? Do the symptom come and go and does the weather make a difference? My symptoms have never been all year. I think it was only in the summer that my hand, fingers, wrist and arm would hurt at night. thank you.