Have you tried any Cognitive Behavior Therapy, or even just reading some books about it? I used to get panic attacks, but I was causing them myself by the stories I told myself, my knee-jerk reactions to perceived stressors/fear, and by the poor breathing I had made a habit due to stress and PTSD.
I needed new stories and better breathing.
I use this a lot:
Box Breathing
Daily exercise, very little caffeine, and a nutritious diet are important tools for me, too.