Welcome to the diabetes forum, fishing-gal. I can help you with some of the medication questions but not the CBD (I guess that's what you're asking about
.).
If a person's kidneys are not functioning well, then it's not wise to take metformin, not because the metformin causes the problem itself, however. The kidneys filter the blood and when they are weak they cannot filter as they should and if you're taking metformin, some of it remains in the the system. Over time a build up can cause lactic acidosis.
Long term use of ibuprofen can actually cause kidney disease so that's why he took you off that.
https://www.kidney.org/atoz/content/painmeds_analgesicsI can tell you that keeping your blood sugar lower to as near normal as you can will help with your kidney function results. Do you know what the GFR result is from the blood test?