sorry for being so LATE finding your 'post'. congtrats. on finding answers to your problem. i like you also found an answer to my high blood pressure after suffering an heart attack a year ago.
my answer was WATER. i know it sounds simplistic, but it worked for me. like you i was limited to what i consumed, like you mainly foods that were unprocessed. although it did the trick and lowered my BP i didn't get much choice in my food.
i first of all drank water to flush the SODIUM from my body, it was until my URINE was near enough CLEAR.it took just over 3 days. since then i have been drinking 4 to 5 pints of WATER a day every day. i still am careful what i eat. i read the labels first now and have set .4 of SODIUM as my limit. i have been doing this for 3 months plus now.
my last weeks readings for eg. were 131/69, 105/67, 125/70, 108/65, 131/68, 79/44, 110/61. what it's allowed is some STRESS space, plus MORE variation in a already controlled diet. i dont have any SPECIAL water, just straight from the tap. anyway it was nice to hear your success story which must have helped many other people with HBP problems, and i hope my findings help you. if you can add anything friend i would be very pleased to hear. thankyou, Tom.