If you can't control your diabetes, with exorcise and diet then you need meds. 220 is way too high. Insulin may be on the cards. Please talk with your Dr.
You have mentioned which level is normally high. Maybe you need to discuss with your doctor, they may have to change the Meds. There's a possible your body may not be responding well to just insulin & metformin. Also if you can try brisk walking for about 1hr especially in the evening
What is wrong is you have diabetes. Diabetes is the bodies in-ability to process carbohydrates properly resulting in high blood sugar (BG). ALL carbohydrates not just sugar. Your body turns all carbohydrates into BG .
I dont know what your "diet" is that you follow. BUT it has more carbohydrates than your body can process. Even the ADA's diet has too many carbs for you OR/AND you need drugs to help your body to process the carbs.
Google LCHF diet
I eat under 50gr of carbs a day, I also take insulin and Metformin.
Carbohydrates or carbs; are what is in food. It creates sugar. Bread and pasta are very big on turning into sugar. In order to watch what says "sugar free" you also need to look at how many carbs and sugar alcohol is in the food. That's a ***** loophole the manufacturers have. Do a calorie and carb counter to target what you need and meal plan. You're already exercising which is an excellent step to controlling your sugar level. Pay more attention to the car seat. Google can help a lot with what foods to stay away from and the app stores have some really good free apps to help with all of this including meal planning
Sugar levels will vary depending when you take your reading.
If you have an infection or virus, that too can influence your blood sugar levels. Steriod medications can also influence your sugar readings.
It may be useful for you to keep a food diary. Do bear in mind portion sizes - you can find information on the web regarding portion sizes of different foods. Do remember that all food is broken down by the body into energy. All refined carbohydrate foods (bread, cakes, biscuits, lemonades) will spike up your sugar levels very quickly. The foods that you should be eating are the slow release energy foods - non refined foods, foods that contain fibre and protein. Do remember that drinking freshly squeezed orange juice is not the same as eating an orange. An orange with its fibre would be a slow release food, some for other fruit and juices. So do bear in mind the types of drinks you are drinking as well as food. Check food labels - low fat foods are not necessarily low sugar.
You do need to speak to your doctor to check your HbA1C levels. This shows your average sugar levels over a 3 month period. Your metre readings only show the sugar levels in your blood at the time of taking the strip test.
If you have not seen a diabetic nurse or dietician that specialises in diabetes, it may be a good idea to see one and this is where your food diary will come in very useful. Your doctor may decide that your diabetic medication may need to be increased or changed to find the right combination that works for you.
Make an appointment to see your doctor and get your HbA1C levels checked.
As a person with diabetes, get your eyes checked once a year - use an ophthalmologist that does diabetic retinopathy screening, this is not the same as having a normal vision check up.
If you can't control your diabetes, with exorcise and diet then you need meds. 220 is way too high. Insulin may be on the cards. Please talk with your Dr.