If I don't tolerate metformin well and Forxiga doesn't work for me, will I need to take insulin?

For several years I had been taking 1000 siofor twice a day and the sugar was regulated on an empty stomach 120 after 150 meals. Unfortunately, half a year ago I had diarrhea, after stopping the siophore it subsided. Currently the doctor has recommended foxigre 10mg twice a day but I still have a high fasting sugar level of 220 a 2 hrs after 300 meals. Are there other diabetes medications that can be used instead of siophore?
The doctor said that the only thing left was insulin.