I used to have the same thing happen to me except that my scary thoughts were about the world coming to a complete end, there being no more God, no more us and it would terrify me. I would wake up and walk around, I was uncomfortable with a lot of anxiety. Most nights I would go to the living room and fall asleep to the tv but it was only a temporary fix. One night I woke up with it really bad. I went to sit in the living room and encountered my only option...I prayed for God to take this extreme fear from me, I couldn't handle it anymore. I reminded myself and God that He said He would never give us more than we could handle. I cried and just continued praying that He would take this all away and give me comfort and peace. Sure enough He did. I 've felt so much better since then. I very rarely get a little scared feeling in me when I allow my imagination to run wild into the hands of Satan. But I always have to remember who can lead me back to comfort and ultimate peace. And when Satan tries to attack order him to "Get behind me, Satan!" (Matt. 16:23)