It took my body 3-4 months to fully adjust to a LC diet. How many carbs are you eating per day. At some times I had to switch my menu around a little to prevent the light headed feeling. I do best around 40 carbs per day, but if I drop it to 20 I will get that feeling sometime. It also takes your body quite awhile to get used to normal bgs. So if you had been having higher bgs for quite awhile, now that you have lowered them your body is rebelling. The dizziness could also be BP related. When I was on a statin drug my BP sometimes dropped below 100 and it was too low. I was always dizzy. I do much better when it is closer to 110/75. Are you on any meds besides metformin?
I also try to keep my carbs at 40 or below. I suspect that I sometimes go as low as 20 or less. I have been quite hardcore about cutting the carbs.
I have just recently started keeping my BS down. I don't know where I have been but I am sure it was high. I was a Coke(cola) fiend for the past few years. That plus snickers bars, cakes, candy, peanut butter toast by the half loaf. I am sure I have been riding high for the past couple years. I was sweating bad during sleep for at least a year as well as blurred vision daily for the same time. I am really surprised that my FBS was only 127 or something upon diagnosis when looking back at my symptoms.
I do not take any other meds but 500mg Metformin. Never been on any meds until now. I never even took OTC meds as I believed my body would work things out with time and if I took meds to fix things, my body would forget how. I know, kinda silly.