@dwelldon Metformin doesn't usually have a dramatic effect on your BG - generally thought to be one point maximum.
It does help you to manage your BG by reducing uptake of glucose a bit, reducing production of glucose by your liver a bit, and decreasing insulin resistance a bit.
Side effects hit different people in different ways. Statins sucked the energy out of me.
The main reported side effects of Metformin are in the gut (which is why it is also known as Metfartin).
So Metformin is an aid, but it won't reverse diabetes symptoms on its own. People usually have to investigate and modify what they eat to improve BG control.
Note I am pointedly not pushing low carbohydrate as the only choice, but it is an option much loved on this forum.
A good strategy is to test your BG for a while, morning and evening, before and 2 hours after each meal. Keep a food diary and you can see what foods are pushing up your BG. If you post what you normally eat and what your BG readings are on a day-to-day basis we can offer suggestions.
In my opinion it is not enough to rely on just HbA1c to work out why your BG control is getting worse.