I used to get full blown panic attacks, so I know how debilitating they can feel.

I don't get the full blown attacks now but I get these long, slow attacks that last 4 hours or so. Not as debilitating as a full blown attack, but still something that's hard to live with. My trigger seems to be waking up in the morning since the attack usually starts then.

But there's also an afternoon "session" (as I refer to these long panic attacks), that seems to be triggered by the time of day.

I said all that to show you that you're not alone. You're among people here that get it.

I have found deep breathing helpful to calm the peak of my attacks. It's nothing special, just in through the nose - as much as I can comfortably inhale - and out through the mouth. If I feel up to it, I hold for up to 4 seconds between in and out. It seems very basic but it is very effective.

The breathing doesn't stop my anxiety attacks, but it does lower the intensity from a 10/10, down to a 6/10 which makes a big difference for me. I repeat the breathing as necessary.

CBT has a bunch of helpful skills that help you even when you're not having a panic attack. I used to think CBT wasn't for me or wouldn't be helpful but I have since changed my mind because I'm in an IOP program where they teach CBT skills and I find them very helpful.

The cold water thing helps but you might need something a little stronger. Try filling a Ziploc bag with water as cold as you can get it and hold it over your eyes and cheeks. You might also want to try an ice pack (one of those reusable ice packs that people put into a cooler), it might boost the intensity of the cold to help ground you again. You can even buy these packs that become cold when you crack something inside them, that way you don't have to keep it in the freezer - you just crack the thing inside and the pack becomes cold.