Yeah that's a lot of slin for the gh dose
Also Lantus is long acting, so it's in your system for a while, which means you're going to build insulin resistance extremely fast. 1g of metformin isn't going to be enough to counteract that.
You're just going to have to keep increasing the slin more and more and more at the rate you're going--not good
Why not just use fast acting slin? Can you take a break from the insulin and lower your blood glucose through other means? Maybe low carb it for a bit, increase cardio, and continue/increase the metformin, maybe a glp-1 agonist like sema/tirz could help?
You need to tackle the elephant in the room--your mounting insulin resistance
I'm guessing your slamming a lot of carbs and/or sugar as well?