What is your height and weight? Are you type 2 diabetic? It's more likely so. I'd like your doctor to add a tablet called metformin
if it's not contraindicated in you.
PP sugar is different all the times. It's not just the meals which determines it. It is also related with your physical activity, hormone levels, content of food, mental stress
etc. Its advisable to keep it below 160 by one drop check method.