Question about blood sugars

So I am new to diabetes, and am slowly learning things I should do. But I have a serious question about blood sugar, and can provide background leading up to the diagnosis that the ER and my doctor stated I have diabetes.

I was trying to get healthier last month because I have been on disability and pounding away soda pops like nobody's business, specifically coca cola, sometimes 6+ cans a day with no exercise due to being on workers comp and my walking being compromised.

I knew I always ran a super high blood sugar, in the 170s sometimes when being checked, but that didn't really stop my coke drinking issue. Well I ran out of water, but had 2 soda pops left, so I was like whelp, might as well use these up and stop buying them, but in this time i had got a glucose monitor to check my sugar levels because I started seeing some bubbles in my pee and was using the bathroom A LOT.

My dinner that night at like 8PM was the 2 sodas, a T-bone steak with mac n cheese, and chocolate ice cream.

I ended up waking up at 1AM to use the bathroom and my sugar was at 200, so I decided not to drink anything else and go back to bed, woke up at like 8AM and it was at like 230, and around 2PM after not eating or drinking anything to see if it would go down it was at like 250, so I went to the ER, to which they said I had diabetes and I was probably going to die if I didnt come in, but my doctor stated I probably couldve dropped it if I just drank literally any fluid(I had not drank anything from the time I drank those 2 soda pops, til they gave me fluids at the hospital at like 6PM). I also found out my A1C is like...10%

Anyway, he gave me a bunch of things to read and told me to check my blood sugar before a meal and 2 hours after, put me on 500mg metformin once a day, and try to change my diet to keep my sugar idealy below 180, but below 200 if I can manage. But since I left the hospital and stopped drinking sodas, my blood sugar sits around 95-115 fasting, and when I eat, it's around 123-140 if I eat fast food, even if it is something like breaded chicken or a quarter pounder from mcdonalds.

My main question is what are the typical numbers I am supposed to be running? Does it mean I am very in control of everything already after a month? My diet really hasn't changed much besides no longer eating mac and cheese, drinking soda pops, and I swapped to sugar free ketchup. Or maybe is the metformin putting in severe overtime? I apologize if this is a lot of information, I am new to it all.