Dibities - Glucose levels. Still high?

My wife Preeti Singh, she was prediabitic earlier as of HBA1c report dated Feb 2021, recently at 19april she dignosed with covid positive. Her CRP was 40 so I had given steroid for 10 days. At 21 may she felt eatchin in hand and legs, I checked her glucose which was 203, I consulted with a doctor and he prescribed Metformin 500 2 times a day morning and evening. I started medicine at today 22/05/2021, these are the glucose levels today. 22/05/2021 - Fasting glucose lavel - 6:46 - 157 - Taken break fast at 9am and taken Metformin 500 - After 2 hour 20 min breakfast glucose lavel is 145 - taken Metformin 500  at 9 after dinner. - night after 1 hour of dinner glucose lavel is 165 PLEASE SUGGEST WHAT TO DO AS GLUCOSE LEVELS ARE STILL HIGH?