Luxe,
Your headache is most likely due to your medications, as you suspect.
I also suffer a headache, caused, I believe, by discontinuing a BP medication-a combination of alpha/beta blockers. I've had this headache going on 5 weeks now. Day and night. A neurologist told me I'd find some relief in walking - and, strangely, I did. Another thing that I find helpful are ice compresses. Of course, both of the above are very temporary, the pain comes back. As in your case, my head hurts across the back. It was tolerable today so I am hoping it's going away! I hope your headache does not last as long as mine has.
Your blood pressure reading is not that bad! You are not much over 140/90 so one or two drugs or a drug combo should be able to control it. I hope your doctor will sit down with you and advise you on lifestyle changes that you need to make. Weight loss/exercise are at the top of the list. That, when combined with proper diet, can bring your blood pressure down considerably. It is possible you might not need any BP medications in the future to control your blood pressure. Some people with stage 1 hypertension can keep their blood pressure controlled through lifestyle changes.
You will need a blood pressure monitor. Get a good one!
Unfortunately, as you are finding out, all drugs have possible side effects. Your body might tolerate some but not others. You have to find one that is right for you. It takes time. How about trying a diuretic since both of these drug classes seem to give you headaches? It seems that the drugs of choice by the three doctors are calcium channel blockers and angiotensin receptor blockers. You mentioned Diovan. My experience with Diovan was not a positive one!
You've had your tests done and all is well.

Finding out you have high blood pressure now is a
GOOD thing! You can do something about it! There are many people walking around not knowing they have this disease. If undiagnosed and untreated, it only gets worse over time. (I was one of them).
Good luck!
Flowergirl