This EXACT same thing was happening to my sister AND me! My sister went through this her WHOLE life, and I started experiencing this later on during college. We were both diagnosed with Acid Reflux. Some things we ate just triggered it and laying down makes it worse and then the acid gets backed up in your esophogus and you throw you. We were both put on Nexium. If I ever don't take my Nexium, I throw up. I take it religiously. Same with my sis. If she takes her meds, she is perfectly fine!
This may or may not be what is causing you to be ill, but I certainly hope it is nothing serious and that you are all well very soon!
