For most newly-diagnosed Type 2's, the disease management information out there, especially on the ADA, is terrible. Meter and strip accuracy is more off-kilter than many realize; calibrate against a venous draw-based blood glucose test. To calibrate my meter on a fine scale, I manipulated my glucose into multiple ranges, and went in for a venous draw each time on my own out-of-pocket money: 120+, 70-120, 60-69, 50-59, 40-49, 20-39. The last four required a water fast at one, two, three and four weeks, respectively. My meter and strips have to be adjusted +20 for 70 and up readings, but only +10 for 60-69 readings. If you're just curious, buy a starter meter kit over the Net (cheaper than what you can usually find in the pharmacies), and whatever reading you get, fudge it by about 10-15 points; you really want to see the trend, not an individual specific number at a single point in time.
Most doctors won't know about various antibody tests that can help refine a diagnosis, and avoid a mis-diagnosis of Type 2 when you really have adult-onset Type 1. If you test pre-diabetic, search on diabetes antibody tests.
Fastest results back to "normal" for most (not all) Type 2 and pre-diabetics come from cutting out net carbohydrates (far below what the ADA recommends), combined with strength training (weightlifting) and supplementing with HIIT cardio. It takes a serious time commitment to do that: 90-120 minutes a day, 3-5 days a week. While I'm diagnosed Type 2 for over three years, for the past two I've not been on any medications, my post-meal ("post-prandial" in medical lingo) glucose stays below 90 at one and two hours after the meal, A1c is 5.3, and cholesterol numbers are in the normal range; I keep my net carbohydrates below 20g per day, roughly half a single, unadorned bagel (my diet is mostly animal protein and green leafy vegetables). Intermittent Fasting helps, as does outright water fasting for 24 hours or longer, for many (again, not all) people.
My personal big revelation was learning the difference from limbic and true hunger, and my personal satiation patterns. Calories In Calories Out is true, but a vast over-simplification because it doesn't address the satiation issue. For me personally, I've settled on hitting at least 200g of animal protein per day, and as much Romaine hearts as I want, with 28g of grated Parmesan and a tablespoon of Caesar dressing on the side, mixed together and used a dip for the Romaine hearts. After that, I can manage the satiation issue with ancillary food. YMMV.
There isn't one single treatment path for everyone, though there are lots of commonalities; I suspect diabetes is a catch-all for a class of a multitude of metabolic disorders, either that or our individual body metabolisms are more wildly different than medical science admits so far. The key to getting back into the normal ranges is apply the scientific method to your body, try one change at a time, measure, repeat.