I'm sorry you are struggling with this. Unfortunately, given the extent to which you are biting & / or picking at your fingernails & toenails, my thinking would be that the normal things one might do in a situation such as this are not likely to be of much help. I presume perhaps you are struggling with some stress & anxiety & that is what has caused you to start doing this.

I'm not a mental health professional. So I can't offer you any professional advice. My thought would be that perhaps what may be necessary, at least initially, is for you to consider getting on some anti-anxiety medication (or perhaps making some med adjustments if you're already on some) & then seeking some counseling or therapy services (again assuming you're not already participating in it) to help you to learn ways to cope with whatever is driving your nail biting & picking. (Cognitive Behavioral Therapy is, I understand, an effective therapy for this type of concern.) Perhaps other members will have some other suggestions to offer.

Here are links to 2 "Ask the Therapist" articles, from PsychCentral's archives, that deal with the subject of nail biting & picking. (There is a link in the first article that takes you to the second article as well.) Also included is a link to an article on the subject of habit reversal therapy:

Out of Control Nail Biting…When Is It Time to See a Doctor? | Ask the Therapist

Anxiety Induced Skin Picking Increasingly Violent | Ask the Therapist

The Golden Rule of Habit Change

I wish you well...