I vote yes to exercise, going to bed early and meditation. Healthy food, a quiet/dark room with a comfortable bed/temperature, and turning off electronics at least one hour before bedtime would be good too! Dreams help our subconsconcious solve problems--when we can't sleep well it hurts our moods and ability to concentrate. Dreaming is good (maybe even the nightmares are processing something you need to face?). Way to take control of what you can control.