I've used different mindfulness exercises to cope with my own hyper-vigilance. The one I like to use the most is "body surfing" or urge surfing. I ride the uncomfortable feelings I have and stay aware of the present at the same time instead of disassociating. After I use that I use the stream exercise. Where things drift by and I put my concerns/worries on whatever passes until I reach a managable level of fear.

I hope this helps. I have had Panic attacks since July last yr so extreme that I went to the ER or wanted to at least 3-5 times a day and this helps me during a 20 on a 1-10 scale Panic. Good luck finding whatver works for you.