Hi! Sleep disturbances are one of the most commonest problems and you shouldn't worry much. The main information lacking in your question is what is your age? If it a recent change, an evaluation into any stress
or depressive symptoms should help. For this you need to visit a psychiatrist
for a detailed evaluation. All said you can at least try out some principles of sleep hygiene
. You should stop or restrict your caffeine , tobacco and alcohol. Start some exercises and take a warm bath at night before sleep. Dont try too hard to go to sleep. In case you dont get sleep, instead of lying on bed and waiting, it is always wise to get off the bed, do some reading and wait untill you get some sleep. Watching TV at night is not a good idea. use of sleeping space exclusively for sleeping and not for any other work. keep the sleeping area, lit dimly.
If this doesnt help you, please dont hesitate to visit an approachable psychiatrist. All said, its not a serious problem and you should be fine very soon.