Hello and welcome!
Nodding off and tiredness can be a symptom of lots of things, such as insufficient sleep at night, eating too many carbohydrates, eating too much at one meal, high blood glucose levels, vitamin or mineral deficiencies, and other things. If your blood glucose levels are high after eating, this could be one reason.
While you wait for your blood results, take some time out to read round this forum and also the main website, and learn as much as you can about diabetes and how you can help yourself. Ask as many questions as you like.