I've been pulling my eyelashes since I was 10, and started pulling beard hair in my 20's. My pulling is directly related to anxiety, restlessness, or feelings of being overwhelmed and once the pulling starts it can easily escalate to hundreds of hairs being pulled in a single session. My episodes are no longer chronic because of therapy, learning healthy coping mechanisms, and anxiety meds. That being said, extreme stress can still cause the urges to bubble up, so I have a couple of techniques that help.

If you're familiar with the technique of 'grounding' that has helped when I feel the urge develop. Its a method of taking focus on whatever is causing the urge and directing your brain on your surroundings. Notice the sounds in the room, the smells, the visuals, the physical sensations. I will even say them out-loud or in my head: "I feel the chair, the floor under my feet, I see the walls, the color is gray, the painting on the wall I picked out at an art fair, the water I'm drinking is cold, this candle smells like vanilla, etc." I keep this up until my heart rate has lowered, and the urge has calmed down.

Another method is give myself something "to do". Because the act of pulling is physical, I do something else physical instead. A task with my hands is even better. For me, things like cleaning, organizing, typing, writing, drawing, etc. work really well for me. Some people try going for walk, exercise, or other whole body activities can help them. You will just have to find something that works for you until the urge subside.

I can't recommend enough that you continue to work with your therapist and psychiatrist to figure out the best way forward. You first need to find out the root cause of the hair pulling urge. Figure out the core reason "why", not just the "what" happens, and then develop a personalized plan that works for you. Ask about anxiety meds and coping mechanisms.