Waking up violently ill- all the time!!?

So for about 3 weeks now i have been waking up in the middle of the night (anywhere from 12 am to 4 am) and feeling *extremely* nauseas. I used to get up an run to the bathroom, but nothing would ever happen, like no actual puking. Anyhow, it continues, and its incredibly uncomfortable, borderline painful, and its not disrupting my sleep. I salivate heavily when i wake up, just as if i were going to vomit, but nothing ever comes out. Im not pregnant, and its not food poisoning. What i want to know is if anyone else has experianced anything like this or if you know what it is. Please no sarcastic answers, i legitimately just want this to stop.