What Causes Severe Pain In The Wrist?

I have pain in my lower arm thumb side of wrist about 2-3" along. I have had this for 2 months. If anything touches it it hurts. If I drag my fingers down along it it feels like it's ripping. I find it hasrd to stretch my arm out straight. The doctor said it's neuritis and that it will heal with time....but how much time??