You're so addicted to smoking that you light up throughout the day, sometimes for no reason whatsoever. You're worried that if you stop, you won't be able to get through the day.
What you need is a replacement: take up a sport as well as nicotine replacements to help you stop. Sport is ideal for you because you'll soon start to feel the health benefits of quitting, ie you'll be able to exercise for more than 5 minutes without collapsing in a heap.
Go and see your doctor or nurse to get you on the right road back to health and freedom from smoking.