Hi. Your improper sleep has caused by bad or worthless dreams which u have said. They develop slowly and if not treated it makes Ur condition more worse. You have to meet a clinical psychologist and get assessed for this. They have dream interpretation analysis  where you have to tell them wat kind of dreams u get often and wat all comes in Ur dreams. Also wat stress u have and some of other details of your life. So they will identify Ur depth of issue level and guide you with exercises on how to sleep and wat good thoughts can be inculcated in you.