If you can't fall asleep without TV or a distraction, you could have anxiety.
Everyone falls asleep on the couch from time to time, but are you doing it every night? Do you feel the need to have a distraction or the noise of the television on in order to let yourself fall asleep? If this is the case, you likely have anxiety.
Michael Breus, "the Sleep Doctor" explains why this is, "there's a thing called autonomic arousal - things like heart rate, anxiety, muscle tension - they rise as you think about a stressful thing. You can't enter into unconscious sleep while those are at an elevated level. Watching TV is a passive activity, you let the stimuli float over you and eventually, you're asleep."
However, it is not very healthy to fall asleep in front of the television every night, so it's important to ween yourself off of it. To do so, it is necessary to treat the underlying anxiety for a good night's rest.