Hello .
Since when u have breathing and weakness problem .
as u mentioned u have done body check up and found low bp ... so have u done any blood reports . And chest xray . If not then do it .. and as per u r profession can u get enough sleep .. and diet . U had any history of fever and cough
Next Steps
if u have not done any blood reports . i will recommend .
complete blood count and esr count . chest xray . if possible pulmonary function test.