Can i really die of hunger? People say i can.?

Im about 6 feet tall and i weigh 118 pounds. Or less.. i have heard that i can die, and i walk much trough my city, and walk home and to school, and have almost fainted.. PLus my dad and mom are/was very skinny too. But i think i eat enough, but i often forget or dont have time to eat, because im scared that i will miss school, or get bd grades. But do you think its more important for me to eat than care about school? Because its almost like i dont have the hunger-feeling, and for me it no problem to go a day or 2 without eating.. maybe its because i have fast metabolism?