I Am Having Incidents Where I Feel What Appears To

I am having incidents where I feel what appears to be a rush of adrenaline. It makes me feel faint and sick to my stomach. I have vomitted several times. I feel a tightness in my chest. These incidents come without warning. They last about 1-2 minutes. They can occur once a week or back to back. Mathis has been occurring since Christmas. I am a 31 year old woman. I have been to a cardiologist who has tested me and found nothing.