What could be the cause for rise in BP?

Hello doctor,

Last year, I joined a new organization, where the working hours are higher with both day and night shifts. Before joining the new organization, I had a stable blood pressure (less than 118/75 mmHg). About five months back, I felt feverish and visited a hospital for the same. That time, I came to know that my blood pressure had risen to 145/85 mmHg. Since then, my life has never remained the same. My parents are not hypertensive. I was having chest pain and sleeping problems from then. I was given Nifedipine for blood pressure and Lexotan for sleep. After taking these two drugs for two days my condition got worsened. I started having anxiety. I reported back to my doctor. In fact, I personally stopped using those drugs.

My BP dropped to a range of 125-130/87-80 mmHg. Since I was not comfortable with the blood pressure, I bought a blood pressure monitor to check at home. I am a food technologist. So, I started working on the food I eat. But, my sleeping problem and anxiety worsened. So, I decided to take my annual leave and that was about three months back. After resting for a month, my blood pressure dropped to 110-118/75-72 mmHg. My BP dropped without any drug, only with the inclusion of fruits and vegetables in most of my meals. I resumed work around two months back. In the first week of this month, my blood pressure had started rising again. I have been looking for a new job, but you understand the economic crisis now. I feel the shift in work is not good for my system. During the morning shift, my blood pressure ranges from 140-125/85-80 mmHg. During the night shift and off days, the BP ranges between 112-119/75-78 mmHg. What could be the cause for this rise in BP? I was thinking that maybe the restaurant food I consume during the morning shift as the probable cause because during a night shift, I eat at home. I am 35 years old. My weight is 74 kg and height is 180 cm (6 feet).