I think it’s normal for people with diabetes to go through phases where they have really good control and phases where they don’t. There’s just so many variables!
For me, I was doing quite well for a rather long time and then, for whatever reason - be it my fibromyalgia onset (the most likely suspect as IBS-like symptoms are part of fibromyalgia), medications that I was taking for that, or some change in the generic manufacturing of metformin, I suddenly couldn’t tolerate the dose of metformin that I was on anymore. If I took my full 1,000mg 2x daily, it was a guaranteed recipe for not being able to leave the house until noon. So I got to where if I really HAD to leave the house, I just wouldn’t take it the night before, or that morning. Well you can imagine what that did for my BG control! And then when my BG control went, along with my sleep from the fibromyalgia, I went into depression and just didn’t care and it was a nasty downward spiral into the worst HbA1C I’d ever had - higher than even when I was diagnosed!
Well, silly me for not talking to my Endo about it sooner. She lowered my metformin dose and I was able to take it consistently again. And she checked out my Vitamin D and B-12 levels, which were both in the toilet, and prescribed for that. I got those in line, got my metformin back in line, and my next HbA1c was back down to 6.5.
My blood sugars tend to run lower in the winter - aside of right around Christmas. Ahem The only thing I can think of is the supposed theory that our metabolism has to work harder to keep us warm, or something like that. I keep the heat at 68F and wear shorts inside, so there may be something to that! I also tend to sleep better when the house is cold, and I know that how I sleep affects my glucose levels.