Yes, that's what I was thinking as I looked at your data. So, it's definitely worth contacting your doctor's office to get an explanation.
I was stable with eGFR of close to 48 for several years. I had to follow my doctor's treatment plan--low sodium, low potassium, take potassium binder and received anemia treatment--but my data was very stable.
I had pretty severe anemia at that point but that was my primary issue; I felt good otherwise. I became quite ill with a gall bladder attack. They removed my gall bladder. I recovered from the surgery without much difficulty. But I had extremely low blood pressure for 4-6 weeks before the surgery due to severe dehydration. That caused a significant drop in my renal function.
My nephrologist was able to achieve a partial rebound in the first few months following that issue. He got my renal function stabilized with an eGFR of 33.
My kidneys remained very stable at this level for another 3.5 years. Last year in December (2016) I became very sick. It progressed from flu to walking pneumonia. It took close to 2 months for me to recover. Again, my blood pressure plummeted. (I've had lots of trouble with it running low and suddenly plummeting since the gall bladder surgery--although these issues aren't related.) At that point my renal function fell into Stage V renal failure. My creatinine was 4.6 and my eGFR was 8.
My nephrologist referred me to a medical center for an outside consult--he has consistently said I should have much more renal function than I've got. The specialist said my blood pressure was too low and causing at least some of the decrease in my renal function. He pulled me off the BP medication I had been prescribed. (My nephrologist had been trying to at least stabilize my BP, I.e., improve the sudden plummeting problems.)
So since August of 2017 I have not taken any BP meds. My BP is higher and fairly stable. My renal function has improved some. My creatinine is now 3.2 and my eGFR is 15 so I'm back to either very low Stage IV or very high Stage V.
I'm not on dialysis yet. I plan to try PD dialysis. I still work full time (as a university professor). I feel fairly well. And I'm able to exercise daily (walk 2 mikes a day and 30 minute workout on my elliptical machine daily.)
So, your blood pressure may be a causal factor for your renal function or a result of your decrease in renal function. My BP issues didn't cause my CKD. But they are an indirect measure of how well my kidneys are managing, overall--from what my nephrologist says.
It's been, in many ways, a full time job to learn what I've needed to learn regarding dietary management and so forth. but your doctor and her or his staff will walk you through everything one step at s time.
I wish I hadn't worried so much in the beginning. It didn't help anything. And, as my case has progressed I have discovered that I am up to the challenge. I'm sure you will be too. This is not what any of us would want. But life does continue. And, with effective treatment, it is a life worth living--you should be able to do most, if not all, of the things you want to do.
Marj