Applying baking soda first thing in underarms in the shower (so it sits there until rinsing) should help. If not, use Listerine for your mouth. Pour some on a paper towel and rub it all around in circular motions inside the underarm, especially if there is hair. Use the minty-flavored. It will kill the bacteria that causes odor. This may not be your case, but if you are a T2 diabetic, insulin resistant,you're more apt to cultivate bacteria in the damper moist areas of your body.
The skin is the largest organ of the body, known as the "third kidney" so it's possible for waste to come through pores, why not the rest of the body? I'm guessing it's a bacteria overgrowth.
When I eat garbanzo beans, especially with cumin, I have smelled it in my underarms. When I stop eating it, it goes away.
If you'e a 3a eGFR, it's an estimate only. Many things can change this instantly under a variety of circumstances. What they need to do is the "Cystatin-C" test, to get a better clinical feature of your kidney function. I'm a 3a too. Mine fluctuates. It can go from 69 to 80 and back again. Dehydration, electrolyte imbalance, poor night sleep the night before the test, lots of things. I hope the Listerine or soda works out and you can get a Cystatin-C.