It will only work if your blood glucose is high before bed because the liver is making too much of it. Could the cause be what you ate for dinner? Cutting carbohydrate for dinner maybe more effective.
Please take your metformin as prescribed.
Metformin doesn't work like insulin, you can't use it to quickly bring down your blood glucose.
I agree with @MarkMunday that it may be very useful to look into what you've eaten to make you go up to 11.2 so you can make different choices next time.
Metformin works on what your liver dumps, mainly in the morning. It doesn't do much of anything about what you eat, so no, it wouldn't help to take it before bed. Besides, if you don't take it with food, you can get some horrible gastro-intestinal side effects, if you don't have them already. It's what you're eating that's getting your blood sugars up, so... Change that? https://josekalsbeek.blogspot.com/2019/11/the-nutritional-thingy.html <-- have a read, maybe it'll resonate with you.
It would help if you filled in your profile so we knew what type of diabetes you have, and what diabetic meds you are on.
You have posted in the Type1 section, but are only asking about metformin rather than insulin.