Diabetes issue. Help to recommend one.

Hi, I have been in pre diabetic stage for long time. In March 2021, my fasting sugar was 108 and H1B1Ac 5.2 and in Sep 2021, it was 118 and 5.8 respectively. I always monitor my blood sugar level at home. This is done by weekly most of the time. I have observed that sometimes my blood sugar levels get elevated to 230 after lunch and fasting sugar gets to 130 levels. I have started walk for 35-40 minutes everyday. Kindly help me to know if I need to start taking medicines or dietary control can help. I take salty oat meal in breakfast and chapatis in lunch and dinner. Very less amout of potatoes intake and white rice. Kindly suggest in what form can I take potatoes. If I need to take medicine for same then please help to recommend one.