Are you on the slow release version of metformin?
I was until recently on what I was told the max 0f 3000 mg a day 2 tablets 3 times a day. When my meds were changed recently I queried the amount of metformin and it was reduces to 2000 mg. When my meds were changed yet again I double checked again and was told 2000 mg was the now recommended max dose of metformin.
If you can't tolerate metformin in any form they are other meds that can be used, but I don't know enough about these other meds, apart from some can reduce your BS enough to give you hypo's.