How Can I Get Control Over My BP ?

I m a 42yo male, over the last 6 months I noticed my blood pressure was occasionally high, I cut out a lot of sodium and fat but it seemed to happen more frequently. I would get a headache and check my pressure and it was 160 s/90 s, after an hour or two the headache would go away and I check my pressure and it s 120 s/70 s. I went to the Dr and he put me on Lisinipril and did labs. My TSH was elevated at 4.19, Vitamin D was low at 21, cholesterol is great and a follow up lab showed freeT3 of 0.93. I don t get the headaches anymore from elevated pressure instead I m dizzy and light headed about 30% of the time with blood pressure of 100 s/40-50 s. When not dizzy my pressures are 120 s/70 s which is what my normal used to be. Any clue s as to what is going on. All of this started over the last 6 months out of no where.