Why am I still sick after 18 months of no-result tests by my doctor?

This is pretty embarring but I don’t know what else to do…. Since November of 2009, I have woken up 99% of those mornings to either throwing up (no I am not pregnant, nor have I been since my one and only son was born 4 years ago), or sitting on the toilet feeling like all my insides were going to come out from the OTHER end. I’m not going to pretend that I have always eaten the healthiest, and I JUST quit smoking less than 2 weeks ago, as well as kicked my 3 diet Coke’s a day habit- but with all the test my doctor has run on me- WHAT IS WRONG? The tests I have had without any abnormal results (in non-medical terms of course): checked my gallbladder, my spleen, I’m not allergic to dairy or gluten, checked my intestines, my stomach, my kidneys (NO stones), and others on a long list that also includes “clear” CT Scans and MRI’s… the only RESULT I have had was I had a 3 inch cyst in my ovary that I had removed 4 months ago. I am 27, 5’6’’, and I weigh MAYBE 112lbs. Pre-this sickness or whatever it is- I weighed a healthy 135 lbs. I am NOT anorexic, I am NOT bulimic, and I do love food.. but that brings me to my next symptom- I rarely am hungry… my doctor put me on anti-anxiety and anti-depressants, I’ve seen the psychiatrist/counselor, (my son’s father used to beat me worse than what you have EVER seen or heard about… boo-hoo, I know), but my BODY is sick, not my mind… at least that’s what I think. But that is why I am posting this- is it my body that’s sick? Is it my mind that is sick? I’d appreciate any insight or answers or opinions… I’m desperate. Thanks…