Okay, so this is definitely an ability you've always had. I used to sleep with the TV on, sometimes I still do, so I understand where you're coming from. Do you want to develop your gift further or would you rather it go away? I hate that you can't sleep at night without a light on. The best suggestion I have is to close your eyes and imagine white light surrounding and enveloping you. Then imagine it doing the same in your room. It will push negative entities out, but will still leave you with any kind spirits. It may help with the energy in the room, though I'm not saying what you have is negative. Even still, it should make you feel more comfortable sleeping, even if the light is on.
As for the spirits affecting you, are you comfortable talking to them?