Don't lie awake for more than half an hour. If you find yourself wide awake, do some other quiet activity away from the bed and bedroom. Go to bed only when you're relaxed and ready to sleep. Train yourself for sleeping. Don't worry if it takes a while to get into a sleep routine.
Routines take time.
Think of it as a body building routine. You have to work up to it. You may need up to four weeks. Change takes time. Sleep on it.