Might be horrible heartburn. I was in sooooo much pain around night time and come to find out it was heart burn! Get well soon :)
Not sure what you mean exactly by "toxic", but I was really uncomfortable and nauseous for the first trimester. Sometimes I would get hunger pains on top of the nausea because I felt too sick to eat. I'd recommend just finding a few things that sit well in your stomach (for me it was mashed potatoes, grapes, and sometimes toasted and buttered sourdough bread) and try to eat small snacks every couple hours.