Metformin made me nauseous as well, although I was able to tolerate 2 tablets a day but not 4.
Ultimately I changed my diet to very low carb, and that was the best option for me as I no longer need to take any Metformin at all. Take a look at low carb or keto diets, so many T2s on this forum have been able to normalise their BG and dump the drugs.