Glucose Number High Lately: Metformin Not Working? Not Enough Carbs?

I'm a 47 y/o male, 5'7", 138 lbs. I've been T2 for nearly 28 years. I take 2,000mg of Metformin. Over the last couple of years, however, it's been harder to control my sugars with diet, Metformin (started maybe 7 or 8 years ago), and some exercise. Even when I do exercise, it doesn't always seem to bring sugars down. I also generally eat low carb. Is it possible that Metformin simply isn't working anymore? My doctor said we could try Farxiga, which I was keen to, until I found out it's $1,000 a month. Metformin is like $6.00. Is it possible I don't eat *enough* carbs? Breakfast is usually a couple of eggs and a Carb Balance tortilla with peanut butter and a wee bit of agave syrup. Lunch might be a granola bar or some meat/cheese, maybe nothing. Dinner is usually a protein and veggies. No sugary sauces, etc. I haven't seen a bona fide endocrinologist in years. My sugars were in such good shape (A1C of 6.0-6.8 forever), so I just saw my GP. (My A1C in Nov. '25 was 6.4.) Now I'm wondering if I should see an endocrinologist again. My sugar this morning was 233. I fasted all day and nine hours later it was 195 after eating some cucumber slices and yogurt. I feel really frustrated. Sorry if this feels a bit disjointed.