What Does Vomiting Sensation, Fatigue And Lower BP At The End Of Exercising Suggest?

hello!i feel very energetic during my aerobic time,but at the end of it,while im doing stretching,i feel dizzy,sleepy,cold air when i breath inside my nose head and have the senses of vomiting.the blood pressure goes at 90:70.im worried about this.whats wrong with me?