Need Help! Stomach Problem!?

I'm turning to strangers for advice because I can't find help anywhere else. I'm scared and I'm positive something is wrong. It all started in December when I came home from work, ate dinner (tuna fish to be exact) and minutes later I suffered severe nausea. I thought it was just the flu or food poisoning. A few days later I developed what I thought was acid reflux and I went to my doctor. He said it was just a stomach bug and I'd be better in a few days. He put me on prilosec. A few days later I went back to him and I still didn't feel better. Eventually, he referred me to a specialist in my area. After seeing the specialist, he drew blood and sent me for a scan of my colon/intestine. He determined that it could be H. pylori, the bacteria in your stomach that causes ulcers. So, he put me on three courses of antibiotics. I was on 2,000 mgs a day! Apparently that's the only way to kill that. I ended up in the hospital because the antibiotics were so strong. I fought through it, finished the meds, and I still didn't feel better! So I went back to the specialist and he said it must be just a virus that kinda "shocked" my stomach's nervous system and I'd be better in a few months. Between these visits, I was in the ER a dozen times. I also had a barium swallow done (where you swallow that chalky mixture and they take xrays of it going through your intestines) I've had numerous blood tests to rule out possible celiacs, lactose intolerance etc. Everything came back normal. So, eventually I was referred to Dartmouth Hitchcock Medical Center, one of the best. They took me in right away and the Dartmouth doctor said something along the same lines as the other specialist. He said that a virus or a bacteria or toxin damaged my Enteric Nervous System (the part of your brain that controls your digestive tract) and that there sounds like slight stomach emptying problems which is causing acid reflux. He said I'd be better in a few months. That was 5 months ago. Recently I've also seen a throat specialist who diagnosed me with LPR, a form of acid reflux that damages your voice box. And I have to mention that I've been on prilosec from december to may and now Dexilant for two months as prescribed by the throat specialist. Yesterday I had bad diarreah and today I feel so heavy in my stomach, like it's not digesting anything. It's horrible. So to recap: I've had: A barium Swallow exam, small bowel follow up exam and xrays, scan and xrays of my colon, xrays of my stomach, intestines, an ultrasound, numerous blood tests, and have seen 12 doctors. They ruled out chrone's disease, celiacs, tumors, ulcers, etc. What could have happened to me back in december that was like a light switch and ruined my life??? I just want to get to the end of this. Please, if anyone has been through anything similar please help me. I've seen 7 ER doctors, two MDs, three gastroenterologists and a throat specialist. I just don't get it. Dartmouth said that he wasn't going to give me an endoscopy based on my age (26, male) and medical history and they are one of the best hospitals around. Also, I'm always constipated, always have an acid reflux feeling, always burping (not normal burps, though) and always always a full feeling in my stomach. I'm hoping someone out there has had similar expereinces cause damn, I feel scared and alone and feel like no one will listen. I know that there's something wrong...Thanks for reading sorry it was so long.