wth is going on

i am 45/F, 140lbs (large frame, look 10-15lbs lighter), run about 30mi/ week and lift heavy 3x/week. i have celiac disease and hashimotos. firstly, my doctor prescribed the LF CGM as my fasting glucose measured high (5.7) and ive been on metformin (1000) for the past six months. when retested, even on metformin, fasting glucose has remained the same. between the two fasting glucose tests, I also did a glucose challenge test which showed high insulin (cant recall the name but you drink sugar water over 3hrs and have your blood taken). because of this my dr is concerned i have pre-diabetes. (BS= blood sugar)

my LF CGM device has shown the following which i find strange: - low glucose (3.7mmol/l) 5x during the night (3-6am) - was not sleeping on my side, woke up and monitored it and it continued to be low for 2hrs. - 7.7 glucose upon waking (8:30am/weekend). this seems high?? at this point i havent eaten for 12+ hours. - drinking coffee and unsweetened soy milk dropped this to 5 (9am). i thought coffee sometimes raises BS? - 7.8 on fasted morning run (9:30-10:30am). thought exercise brings down BS? - zero sugar/low carb whey protein shake spiked from 5.5 to 9 (10:45am). low carb, sweetened with stevia, why would this cause a spike? - eating carbs (orange, cereal, corn chips) results in my glucose falling (6pm after not eating since 12 noon, this was two separate days, cereal was keto granola). i thought carbs raised BS? - going for a walk after eating results in my glucose rising 2pts (this was around 1pm after eating low carb lunch).. again thought walking after eating lowered BS?

the above seems the opposite of what should happen based on my (limited) understanding of blood sugar and insulin. i will obviously make an appt with my doctor to discuss, but if anyone has any idea whats happening to me i would be curious to know in the meantime. thanks in advance.