Sometimes I can have that feeling of impending doom for hours, non-stop, it can vary in intensity and peak, when it peaks I feel like I'm losing my mind and everything gets somewhat tweeked, like looking at a reversed sped up tape with a bunch of effects, people say a panic attack can last max 45 minutes, but sometimes for me it just goes on sometimes for 7-12 straight on hours, when I try to relax and breathe and sleep, it just creeps up on me just as fast and even harder.. Help