low blood pressure, tired & can't exercise intensely

I have had low blood pressure all my life, today it was 76/50. I am tired nearly all the time. My diet & weight is good, i do not smoke or drink, i am not depressed.I have been seeing a v educated experienced natropath for several years to try to get to the bottom of it, & have done candida diet, parasite cleanse etc. He says now theres not much wrong with me, except my adrenals need herbs. (again). I do get stressed easily, but also do stress reduction things like meditate etc. All blood tests appear normal, but i have very little energy, & can get lightheaded & cold when i exercise intensely for more than a few mins. I don't really want to take drugs, but am fed up with being unfit & tired all the time! I am 41, female. Could it be low blood pressure? it seems i have looked at everything else it could be!

ROLE- am not a caregiver!! there was no category that fitted me