A day ago i had black stool but now normal. feeling light headed and short of breath should i see my doctor?

Yes: you describing what could be known as melena (digested blood in stool). Given your symptoms of anemia this likelihood is high and you should see your doctor. I hope you will feel better.

Black stool: Black stool can be due to bleeding and light headedness can be due to anemia. If these continue you should see a doctor.

See you doctor asap: Black stool, light headed, and shortness of breath are signs of a GI bleed with a significant loss of blood. Have you ever had ulcers? See a doctor ASAP. I would recommend having your blood checked for anemia and an upper endoscopy. If that is normal, possibly a colonoscopy.