Probably you are a creative person and think a lot of them. Your imagination could be the manifestation of your ideas and thoughts. When you get such imagination,  log them in a journal as "Palest of ink is better than brightest of memory ".  Once you practice your mind calms down as it is convinced that imaginations are being orderly registered.  That will give you peace of mind and allows to sleep. Before going to sleep,  practice some non-doing activities.  Watch a hilarious serial, do meditation for atleast 15 mts without thinking but focusing on your inhalation and exhalation. When you are awake & active during the day, retrieve the imaginations and choose whether to talk about the same to others or you work on them yourself. Work on your strengths that worrying.