I wish I could help. My natural response to anxiety is to implode and shut down. I had a roommate though who used to get these attacks, and I would put my forehead close to hers and just speak quietly to her. My voice is fairly low, and she told me it was a soothing sound that she could hear and respond innwardly relaxing to.

It might help then to think of a voice that you find soothing to listen to. Maybe even a song. Learn about your strongest sensory imput signals and seek out accordingly. Maybe it's a favorite visual, smell, sound, texture or taste. My roommate moved about a year ago to live with her girlfriend, and I used to have to still drive to their new place to help her breath. I had to teach her gf how to do it, and to make her voice lower while helping.

Good luck.