I’m 60 and also have sleep apnea and fatigue. Perhaps your CPAP pressures need to be tinkered with - sleep apnea can change over time. I use an alternative to CPAP, an oral appliance called a “mandibular advancement device.” It’s easier for me than CPAP, though it’s no longer quite as effective for me as it used to be.
The kidney trouble might indeed be from medication, but it’s moe likely to be a single, specific one than the whole collection.