I need answers. whats wrong with me?..?

Okay. for the past six months i have expirenced a lot of problems. the sight and thought of food sickens me. everytime i do eat, i want to throw up. I gag a lot. my head hurts and i get dizzy, and i have been losing a ton of weight. Sometmes it gets hard to breathe and it feels like something is blocking my throat. Also, most of the time i feel like fainting. I need an answer or an idea of whats wrong with me. Please help or give ideas.