Why can't I sleep without tv on, else my mind race through random thoughts, is this normal?

Maybe. The problem with sleeping with a tv on is that it can promote poor sleep hygeine. Watching tv can promote stimulating thought. Further the light from the tv may affect the natural production of melatonin which is highly affected by light. I would suggest taking 30-45 minutes to "calm yourself down" before actually going to bed. Reading, meditating, relaxing before bed are the best ways to start.
Sleep hygiene. You describe your thoughts as racing - is this only at night? Are you under stress or is this your norm? Start by changing your habits- no tv in the bedroom, no work piled on you dresser - just a tranquil room. Buy a machine that makes various background noises like the sea, rainfall, etc. A lot of people use these with success. Consider seeing your doctor to discuss racing thoughts and keep a log.
Sleep. Yes you are normal. Many people use the tv, radio or music to put themselves to sleep, as opposed to many who prefer a quiet dark room.