Hi and a warm welcome to healing well
Nail biting can be definately be a symptom of anxiety. If your doctor is "dismissing" you on this issue I agree with Lyn on taking it up with your therapist (it might also be worth thinking about dismissing your doctor if he doesn't show you enough respect!!)
Let us know how you get on and please don't feel wierd about posting your symptoms, we all have some funny ones here !!
I alone can do this, but I cannot do it alone.