Most hypoglycemics find they need to consume a small snack or meal at regular intervals during the day. I am mildly hypoglycemic but can attest that if I have eaten a light breakfast, no mid-morning snacks/meals, and take a late lunch (even at 1:30pm), I will have symptoms for rest of the day. As you described, you laid on the couch all day without eating or re-supplying your blood sugars [not good!].
Try to keep a supply of natural, fruit juices on hand, or fruit and nuts, for ready consumption. If you're not allergic to off-the-shelf sliced, whole grain bread w/peanut butter, a quick sandwich will usually help stabilize the blood sugars so that you can prep a heartier meal, or at least drive to pickup a hearty meal.
At a young age, it is easy to be distracted by the demands of work, play or other obsessive activities which can lull you into low glucose levels & hydration if you are not eating and drinking.