So after visiting...
...my doctor the other day, he's now put me on a rapid-acting insulin "Apidra". It comes with a pen injector and the needle heads I use for the Lantus injector I can also use for the Apidra injector. I still am taking the metformin, but the gliclazide and the januvia have been stopped. After 2 days of using this new insulin, my sugars have improved. Before, the pills I was taking suddenly decided not to work anymore, and my sugars barely went below a 20 mmol/l (360 mg/dl). Now, they're at least 10 points below that score. I still have to experiment a little with the dosage, but with an improvement like that, that shouldn't be too difficult.