A stressful point in your life, thoughts running through your head, anxiety? Those are very typical reasons to wake you up in the middle of the night. If you are prone to worrying in general, worrying about your sleep might trigger a very unpleasant circle of restless nights.
Usually, avoiding negative thoughts would not be the best way to ease anxiety and worrisome thoughts. A much better strategy would be to limit the time spent worrying overall. Take 15 minutes at some point during the day, well before bedtime. This can be your personal thinking hour. Try keeping your day otherwise free from thinking about the worrying thoughts. If worries arise, push them back till the next thinking hour.
Example Habits to try
List Your Worries
Falling asleep may be difficult when anxious thoughts flood your mind. It is hard to calm down and...
Åkerstedt, T., Kecklund, G., & Axelsson, J. (2007). Impaired sleep after bedtime stress and worries. Biological Psychology, 76(3), 170–173.