I've been having this too. I either think about family dying and lately myself. Any little twinge around my chest I start to go to that place. I happens during the day but not as bad. The thoughts are so intense that I can't sleep. They keep going over and over in my mind. It really is more of an anxiety attack with everything I feel. It's hard to sleep when it gets that way. Distraction is what helps. I try something and if it doesn't work I go onto something else. And breathing exercises do help too.