Are you familiar with www.PCRM.org - put together by the Physicians Committee for Responsible Medicine, all vegetarian and vegan MDs - ?
Once you've been there a few times, you'll find there's lots of helpful info - especially on their sub-site, www.NutritionMD.org
On the Home page of PCRM, they have a link to nutrition questions, incuding a list of FAQs with one on HBP: http://pcrm.org/health/
What I got out of it is:
Salt and things containing a lot of salt, like olives, are #1 culprits in HBP - along with tasty "prepared" foods (things in cans & packages).
So it could be that the "mystery" of a vegetarian like you having HBP is solved -
not because you have a lot of salt & olives these days, but because those were your favourite foods for decades and decades, along with other salty foods. And as you know, when we overindulge in a food item (like salt or dairy or whatever) our body can become over-sensitized to it so that we react very strongly to eating even the tiniest amount of it.
It can take years to de-sensitize our system once it is in that overburdened state -
which in your case would mean cutting out all salt:
obvious things (olives) as well as subtle things (packaged and prepared foods of just about any kind). This may not bring your HBP down immediately so you'll need to be prepared to stick with it for months until your system has recovered a bit from its sensitivity.
The Up side is:
1) You will be on a very healthy dietstyle, so your health overall will improve - which is a big plus at any age.
2) You will be amazed, after a month or so without salt, that you will begin to taste the natural flavours and natural "saltiness" in vegetables in a way you never have before. (My husband & I were on a salt-free diet for years to help his health.)
3) If you stick it out long enough without cheating, you won't crave salt (I remember that even lightly salted foods tasted way over-salted to me when I was on the salt-free diet).
4) You will be able to reduce the medications, which have dangerous side effects.
5) I'd have thought your HBP would come down bit by bit - though it's not likely to start happening overnight. It's possible you've got the equivalent of extreme chemical sensitivity. You'll need to go for the long haul with this thing if you want to bring your BP back to normal naturally and get off medications & their animal contents. You'll need to decide if it's worth it to you, spiritually and otherwise.
Here's a page from the PCRM NutritionMD website (you can go there from the PCRM home page - look for NutritionMD in the list of links): http://www.nutritionmd.org/
Then this other page for doctors: http://www.nutritionmd.org/
This is the Chronic Kidney Disease section: http://www.nutritionmd.org/
You don't have CKD but it discusses things you can implement now (even mentions salt sensitivity!) to bring down BP and strengthen your kidneys.
Well, that's a lot of info. Take it bit by bit!
Feedback from a friend: Apparently HBP may be reduced by taking high quality Celtic Sea Salt! There are 80 minerals in Celtic sea salt - and some people with HBP are mineral-deficient, so taking 1/4tsp or 1/2tsp or even 1tsp of Celtic sea salt a day (sprinkled on food or stirred into a glass of warm water) lowers their blood pressure. But it needs to be genuine Celtic sea salt, not some easy-pour refined version.