how old are you/if you are at your 40's or so then this is normal that we cannot get sleep that fast unless we are very tired for the whole day and our body and mind is looking for a good sleep.

But if you are younger?then better prevent drinking caffeine and Soda,try not to smoke and alcoho also because alcohol immunity gives sleep hard to find.

Exercise daily and lessen your thinking as problem can be solve one at a time.