Could The Decrease In My EGFR And High Nitrogen And BUN Levels Be Due To The Water Pill, Or Are My Kidneys Causing Issues Again?

I had a low EGFR and high creatine levels. I stopped most of my medication s and went on a vegetarian diet and my kidney functions went back to normal. My EGFR went back up to 80. My blood pressure was still remains high so my Nephrologist put me back on a water pill along will the medication I was already taking. My EGFR now went down to 67 and my nitrogen and bun levels are high, but My creatine is normal. Is this due to the water pill or are my Kidneys causing me problems again. I do drink only water throughout the day. Thank you.