Well I Ran My First 800 Ever Race And Well

well i ran my first 800 ever race and well i tried to stay on top of the race i was sprinting but felt nothing really and around by the 300 mark I looked at ny hands and they were pale it followed by them also being numb and later around the 350 my feet also got really heavy and i just gave up on the race after that i was a bit dizzy so i just drank water and rested for 30 mins