I've had that before, and sometimes I have that when processing trauma with my alternate personalities in therapy. My therapist would help me to refocus and ground by feeling my feet on the ground, moving my arms and shoulders and body around, and sometimes breathing. Whatever works in the moment so that I'm not panicking or dissociating or having too many flashbacks at once.

When I'm hyperventilating, the breathing in the paper bag works. But if you don't have that, I tend to sit own, bend down by putting my head close to my knees, and then moaning. Sometimes that helps me to get my breath back. Sometimes I pace and walk around, but that might make things worse. I have to feel safe and training my eyes, ears, and touch/feeling feet on the ground/feeling something safe in the vicinity - or even just feeling my body again - to feel safe. Taste is tough to feel safe, and some people lose their taste or smell, so I don't go by those senses to ground or feel safe anymore. I am also paying tribute in my own way of grounding to those who lost their smell and taste, too. I think of them and my empathy for them helps to ground me sometimes - not always.

But when you cannot think while panicking and hyperventilating, the breathing thing or movement thing helps - esp. if you have a paper bag.