Dear,  don't worry Consult any physician  to rule out cause behind it. Avoid self medication and diagnosis  and treatment In ayurveda  excellent remedy available so u wl  get benefit definitely Consult  any physician 

The actual reason can be analysed only after a consultation. Some of the cases needed medication other than diet and nutrition in order to stabilize the condition.

BP is just a parameter to check wellness It is of significance if u have decreased exercise tolerance or headache, giddiness etc symptoms If you have BP 100-120 /65-80 and no symptoms like weakness,giddiness or fatigue Then it's of no significance It's normal If you feel tired and thirsty have good amount fluids Increase liquid and semi solid foods like daal, smoothies, in your diet along with daily intake of juicy fruits Check hemoglobin As low Hb can b cause of low blood pressure and weightgain