I would suggest you to add fat to stop weight loss unless you think you have any other problem/condition.
Testing is entirely upto you, I tested about 10 to 15 times a day earlier when I was diagnosed, now that I eat low carb and I roughly know what will suit me and what would not I only test 3 times, fasting before dinner and after dinner just to get an idea. If i have anything high carb I definitely test 1 2 and 3 hours.
What is your BMI just out of curiosity.