Had Chest Pain And Headache. What Could Be Problem?

Hi, i am a 21 year old female, in the past 6 months i have had multiple episodes of being light headed, my heart beats really fast, i find it hard to breathe and my chest becomes heavy and i get the shakes. The last time this happened I had chest pain, the time before that it woke me up in the middle of the night and I threw up. I went to urgent care yesterday and had had an ECG done, i now have to see a cardiologist because he said my heart rate was fast, it was 86 bpm, i also have had headaches everyday for the past 2 weeks and although advil helps as soon as it wears off, te headache returns, what could be going on??