After I was in therapy for quite awhile I quit worrying about symptoms and concentrated in trying to understand and work with underlying causes? I bit my fingernails until I was about 53 years old and then it gradually stopped. I finished therapy when I was 55. I imagine therapy and resolving issues had a lot to do with a lot of my behaviors/habits/symptoms as I don't consider myself as having very many I have to get rid of.

If it makes you anxious to think of picking, then work on something else that might impact the picking. You can do some substitution; I'd wear socks most of the time so I wouldn't pick my toenails/toes. My stepmother tried everything with my problems, both fingernail biting and toe/nail picking; made me wear gloves out to play (made me very popular with the neighborhood kids as you can imagine), once even tried to spray my hands black with spray-paint, getting it on my favorite blouse. She tried the bitter stuff you put on fingernails and ridiculed me, offering her own toenails for me to chew if I'd chewed my fingernails too far down or pulled off everything that could be pulled off my feet?

Give it a rest/ignore/"allow" it. Your mind and body are doing their best to deal with overwhelming anxiety. Be thankful! I use to have really bad dreams and hated that until I realized that having bad dreams at night meant I could "function" during the day. It's always a tradeoff, something has got to give and nothing is going to get fixed quickly.

Substituting is a good idea but just being gentle with yourself and then going after what is really making you anxious and conquering that worked better for me.