I agree with Cuchculan that a silent room s sometimes not the best options. If you have issues with sleeping and you have a quiet room often the loudest thing is your internal voice saying "I must get to sleep!", "look at the time!", "You are going to be so tired in the morning!"... and this really is not helpful.
A good idea is to find something that distracts you... but not stimulates you. For example the TV works for some but can stimulate the minds of others too much. I personally would not recommend the television, however, reading before bed can be good, but again, thrillers and horrors are probably not a great idea.
The old saying of counting sheep is not as lame as it sounds. If you are visualising the mundane and boring sheep and focusing all of your attention on this then you don't have space in your mind for thinking about any other issues.
There are a million and one techniques that you can try but my suggestion right now would be to find something that you can direct your mind towards that will quieten it and replace the noise of your inner voice.