Perhaps you need to be having a medication review with your health care professional. For instance, there are alternatives to the proton pump inhibitor that you mentioned if you are still having problems related to stomach acid. I have acid relfux and it is controlled very well by omeprazole.
As far as I know, a maximum dose of metformin 2000 mg a day reduces levels by 1 -2 mmol/l. If you are not taking this med then you may want to eat as few carbs as possible so that your levels don't rise that much.