I Need Help!!!! I Have Been Not Feeling Good For

I need help!!!! I have been not feeling good for the past 3-4 months. I have been to the doctor but they don't seem to be giving me any answers. I am having severe stomach pains and I have been throwing up everything I eat ( even throwing up when I don't eat ). I don't know what is wrong but it really hurts and I just want some idea of what is wrong