Dear, the duty of your mind is to think. You cannot control your mind's thinking. But certainly you can divert your thinking. You can make your mind to be always positive by engaging in creative activities, hobbies, games and passionate towards whatever you do. Thereby you can reduce your stress
and tension also. Once you can do this, loss of proper sleep and stress also can be made normal. Please provide me with more information, I can help you with this. Take care.