Hi, I suffer from panic disorder and GAD, PTSD 

For the last 3 years daily I get bouts where I feel I can't breath (the usual I'm sure you've had it) and my anxiety kicks off until I can feel that I have taken a deep breath normally this will last a hour or two 

It's now been 6 hours with this one so I'm annoyed (had a night terror been on edge since) 

Basically feels like my lungs are on fire and I can't take a deep breath or get enough air - i assume I'm hyperventilating but does anyone have a remedy for this ?