Set yourself a plan.
Test as soon as you get up in the morning (after washing hands) before doing anything else.
Test before each main meal
Test 2 hours after first bite
Test at bedtime
If you are continuing to exercise a lot, test before, during and after.
Keep a food diary including portion sizes and record your levels alongside with notes about exercise etc.
Look at the rises and keep them under 2mmol/l and when you improve, keep them under 1.5mmol/
More than that and there are too many carbs in that meal, so look at the carb portion sizes and reduce them, then try same meal again.
If that doesn't work, eliminate something carby
Try to avoid too many carbs at breakfast.
The food baddies are bread, rice, pasta, cereals, potatoes and most fruits, plus anything made with grain flour.
To avoid hunger, increase your fats. Ditch any low fat or light products you have and eat real natural food.
Have a look at what you can eat here
https://www.dietdoctor.com/low-carb/60-seconds