Hi Roshin. BP medicines are supposed to be taken forever even after BP is under control. It is because of the medicines that your father's BP is under control. Listen to your doctor and do not discontinue medicines. I think u meant BP is 120/ 85 not 120/ 35, right?
Diastolic is quite low. the normal is 120/80 and you mentioned 120/35 if it is this then the Diastolic is quite low.Better get it checked again. Bye