Hi I'm Having Sharp Pain On And Off Serval Times

Hi I'm having sharp pain on and off serval times a day .. Not first thing in the morning so much but starts a few hours later ... I did stop taking a mild blood pressure med maybe 6 weeks ago .... I hate medicine ... It was a water pill atenolol .... I just started an exercise program ( walking ) always had a mostly healthy diet .. I want to lower my pressure naturally .... Now it's 131/78 ... What do you think it is ?
Thanks so much