A few years ago I would have several panic attacks a night. This lasted for about 3 months. I thought I was going to lose it. I would wake up and be scared out of my mind and shaking. I wasn't afraid of anything I could pinpoint. Just afraid. I would go back to sleep and wake up a couple of hours later to the same thing. It hasn't happened in a while (a year or so), but I haven't felt the same sense. I feel like I can't think clearly.