I Am Presemtly On Bisoporol For Heart Failure Due To

I am presemtly on bisoporol for heart failure due to high blood pressure which affected the heart muscle stage 4. I amtrying to control blood pressure by natural means and it varies during the day being higher systolic in the morning but goes below 130 in the afternoon and evening. I would like to get off the bisoporol (low dosage 2.5 mgm. as I have side effects , freezing cold feet, cough, and last blood test showed potassium abnormal 5.2 and GFR abnormal. I am concerned that kidneys will be badly affected if I am on this for life. However I do not want to have a heart attack. I am slim healthy diet and exercise.