Its always good to continue medicine your prescribed.
Have you had a 24 Hr ABPM test? Its gold standard for BP evaluation.
Without the full medical history, its hard to know whats happening.
How are your Blood Sugar levels?
Is your Kidney function ok?
Any Adrenal gland issues?
Any thoryoid problems?
Have you had an Echo test for Heart function? If so how was your EF?
These are all important items to help you establish whats going on
Im not a doctor, but if i were in your shoes, I would make a list of questions and make an appt with the cardio.
Try and get some satisfaction about your BP and dont be afraid to express your concerns.
Im not sure if the surgery has had an effect. But thats question number 1 for your list