Welcome to HCM,
After going through your history,You have Essential Hypertension
as you have been investigated for Hypertension and no cause is found in most of the cases of Hypertension >95% there is no cause is detected.
You should quit smoking
and alcohol, continue exercise as it helps to keep fit,and other life style modification like pranayama.
It is proved beyond doubt scientifically that keeping BP in normal range with medicine is beneficial if BP is not controlled by only life style modifications.
It is true if in most cases treatment continues lifelong but there are more advantages of taking medicine regularly so please continue your treatment.