The only way to know if you are experiencing low blood sugar (hypoglycemia) is to check your blood sugar (glucose), if possible. If you are unable to check your blood sugar, treat for low blood sugar by following the Rule of 15.
Congratulations! You should now have a better understanding of how to identify and manage the symptoms of low blood sugar (hypoglycemia).
Don't forget to check out the Starting Insulin, Why Insulin? and Living With Diabetes sections to get the basic knowledge you need for a successful insulin treatment journey.
References