I can understand exactly what you are going through as I had suffered from panic attacks for many years.
The attacks are much more under control now because I have finally realized two things:
1. That I would forget to breathe when I felt threatened or emotionally upset or under any other circumstance that would normally cause me to panic or feel anxious. When I read about this some time ago, I found that I really had been forgetting to breathe. So now, I just try to remember to take slow, deep breaths before I can even start feeling anxious. It works remarkably well. I hope you'll try it.
2. That *I* am in control...not the anxiety. I now say to myself, "I am strong, I am healthy, I am calm. I am NOT going to let this anxiety feeling that I feel coming on control me."