I chipped a front tooth slightly 13months ago, just few weeks, i started feeling this sensation and/or numbness, i haven't gone to any clinic for any treatment or gone to any pharmacy to purchase whatever drugs..?

A dentist should examine you to determine the problem and advise you. Perhaps only a bonding of the chipped tooth is needed.

You traumatized the nerve in the tooth and after a year the nerve is slowly dying causing these symptoms. You need to see a dentist for an exam and x-ray and possible root canal treatment. Purchasing medications is not the answer, only a dentist can help you.

You should have seen a Dentist when your symptoms first appeared. Time is not your friend. Problem will only get worse (more expensive). Additionally you should have had 2 routine examinations/professional cleanings by now, at which your Dentist could have treated you properly. No pill, polities, homeopathic, computer click, over-the-counter medication can treat your problem. See a Dentist, now.