I am 17 years old, Every night time i feel really sick, but only sometimes i vomit, And every time im hungry im getting full after small amounts and sometimes the thought of food makes me feel really sick. i also feel really weak at times. I also suffer from really really unbearable period pains which also lead to vomitting Its asif i have a sqeezing pain on my stomach, ive felt like this a numerous amount of times over the past year and have had a number of blood tests but nothing is showing, what could this be?