Even after taking medicines, my blood pressure levels are not under control. Why?

Hello,

I am having high blood pressure. I am 40 years old male. I have been using Lodoz 2.5 mg medicine from last 8 years and always my BP levels are below 120/80. Here is my problem:-

Last 10 days my BP levels are increased a lot to 160/90 and high heartbeat. I visited to my primary care provider and he took the EKG and everything looks good. He suggested to change the medicine to Lisinopril 10 and 20mg. I started using lisinopril 10 mg, first two days, my BP levels are controlled then day 3 onward, my BP levels are continued to spike up to 160/90 again.. after 5 days, I started taking the lisinopril 20 mg tablet but still BP levels are not controlled. on top of that some side effects like no sleep in night, headache and dizziness.

I sent a message to my provider but waiting from response from him. Then I stopped using lisinopril 20 mg and start using my old medicine Lodoz 2.5 mg 2 tablets a day from last night.. Last night I was perfectly fine but morning onward, BP levels are 160/90. I stopped using salt intake in my food since last 1 week and no chest pain. I don't know why I am having this problem in spite of taking lot of health precautions ..My father also has same problem but need your advice on medication what I am using. Would really appreciate reasons for not going down my BP levels. I do 2 to 3 mile walk every day. I am 5.8 inch height and 70 kg weight. Really appreciate your response on my query.