What am I ? I do not feel normal?

Okay so please do not laugh.. I am 17 years old and ever since I was little (about kindergarten) I have noticed I was always different from my class mates and as I got older, I got friends, but they noticed Im different too... at times, I would get sick for no reason and have a horrible burn in the back of my throat, but doctors would not see anything wrong. I also have random heart spasms where I feel like Im going to faint if I do not lay down or eat something. I am average weight for my height of 5' 4.. I am pagan, and I practice witchcraft, but my question is, is there any way to tell if I could be a different species? I know... far fetched but I need some help because no doctor knows what is wrong with me. I have been going to doctors since I was a kid.. help? please?