It is not really possible to guarantee not having a stroke, but to put things into perspective, anyone can have one due to different circumstances. Any of us could have unknown aneurysms in the brain which could erupt at any moment causing a damaging bleed. Someone else may correct me on this, but I would have thought with such low blood pressure, you are at quite low risk. Your arteries are quite relaxed and not under the stress that mine are for example. My blood pressure is not far off double yours. When I had my first heart attack I used to think negative thoughts from the moment I woke up, such as, will I have another heart attack today, will I have a stroke. Nearly 5 years later I'm wondering why I bothered with that anxiety. Nobody can say if you will, or if you will not have one. Put it to the back of your mind and enjoy life. The less you ponder about such things, and reduce the fear, the healthier you will be. Everyone on this planet is in the same boat, nobody knows what is happening in every artery in their body.
Vitamin B12 deficiency symptoms include fatigue, chest pain, dizziness, low blood pressure, migrane, elevated homocysteine. To avoid misdiagnosis, always request your lab results.
Vitamin B12 serum - optimal is over 800pg/mL or 600pmol/L.
Homocysteine - healthy is 6.3umol/L. The higher the homocysteine level, the more at risk of heart attack and stroke.