For me, to go back to SUCH a time when I was 16-year-old kid, I'd have to travel back all the way till 1991.
Like you, we were also vegetarians (as my Mom and kid-bro still are). So far as I can remember, for "breakfast" I never liked, back then, to have anything really – just an instant "coffee", with dairy-milk and sugar, when I just got up, and later, for 10-am-meal, would have two Sandwiches = either with Hummus, or some sort of a (dairy) cheese and, of course, sliced cucumber and tomatoes at each of them as well. Later, for an intermediate snack between this a Lunch, had yet another such Sandwich, and, after school-day ended, might buy myself a small sweet snack, at the kiosk next to it, to last me the 20-mins-walk home (as I ALWAYS WALKED). Then, for Lunch, would normally have like two or three "Tiv'ol" vegetarian schnitzels (or hamburgers or another such "meatlike" stuff – all made of Soy and extremely industrial products; they do still exist today, but, even the Vegan ones, I RARELY touch; they are SOOOOOOOOO processed, with lots of chemicals and sodium and what-not), typically with lots of Hummus 🙂 , and lots of Orange-Juice next to it. At four pm (I was SOOOOOOO nerdy and pedantic back then!! 😉 ), I'd have my second coffee (as I still do today), with a slice of Cake, and/or Chocolate, and or sweet snack next to it; and then, for supper, I'd either have some sort of fried eggs with Salad (No, GrandMa, I HATE avocados!! No, I will NOT touch my Salad, if it will contain that!! Please, understand!!"), or (if left to my own devices) a toast, with various dairy-cheese.
Perhaps, if my channel would show any growth some day, I might try to veganize ALL of this stuff and upload a vid like this one, too.