I'm not sure if I'm even falling asleep at all or how much time is passing, but I will be half asleep and all of a sudden im awake with my heart starts racing and I panic. then I fall back asleep and it happens over and over. does this happen to anyone else? it didn't start until recently and it makes me feel like i barely got any rest. I am having a ton of nightmares recently, but this happens before I'm asleep long enough to have any, or at least I think so.