You have not mentioned your age and your recent BP reading.
Blood pressure is the pressure exerted by the blood on the lateral walls of the arteries. It varies physiologically on the build of the person, diurnal variation, after physical exertion or emotional stress
. As long as you do not suffer from any symptoms, do not worry.
It would be ideal to check your blood pressure and maintain a chart for a period of 1 wk . If the variation is not more than 10-20 mmhg, both systolic and diastolic, be rest assured nothing is wrong with you!!!
Start doing breathing exercises/meditation
, which would help you relax....Also eat at proper intervals and follow a healthy diet and lifestyle, which would help in increasing your weight.