Suggest Treatment For Hypertension

At the age of 27, I am suffering from Hypertension. Whenever I am checking BP, its varying like 100/140, 100/150...some times 110/150 or 100/120. Doctor advised me to take medicine for 1 month (Xirtam 20mg). But I am very much confused, if I started medicine from 27th age, this will be a permanent dependency for me or only need to take for a short term? I have done all other testing; there is no specific reason for hypertension. My BMI is around 28, is this will be a reason? I am started with a good diet plan, in one week reduced 1.5 kg and my target to reduce at least 7 kg. Please let me know, can I go for medicine or continue with good exercise and diet? Is drinking green tea and having one spoon of olive oil with meals doing help to reduce BP? Please help with you valuable advise.