I Have Had Severe Issues With Nausea And Fluctuating Weight

Since 2006 I have had severe issues with nausea and fluctuating weight (dropping 20+ pounds at a time, then gaining it back within a few weeks). I have also had constant high bilirubin levels (3.5 and above). The nausea is random and has no particular pattern. I have already tried the following remedies for the nausea: - Low protein diet - High carb diet - Milk exclusion - Fat exclusion - Sodium exclusion - Aciphex - Protonix - Various nausea medications None of the suggested remedies have helped the problem or made them worse. I've had clear ultrasounds that come back completely normal as well as clean blood samples with good cholesterol levels and white blood cell counts. The only oddity is the high bilirubin. Just recently I've started to have problems with high volumes of Aminolevulinic Acid, causing my urine to have a very moldy odor. This has only been happening for a month or so. The only thing that I have found to ease my stomach (not stop the nausea in whole, but make it a bit milder) is to ingest high amounts of sugar (soda, marshmallows, candy, etc). H-Pylori is negative. I also have started to get severe headaches and mild dizziness along with some stumbling. I've also started to get nosebleeds for the first time in my life. Another large problem is extreme fatigue, causing me to need at least 12 hours or more of sleep a day to even feel somewhat awake. Currently I am seeing a GI specialist and there are no signs of ulcers or any other stomach issues. As said before, ultrasound came back clear and all other organs are normal looking. My doctors are currently stumped and I am hoping to get a few ideas to bounce off of them as it seems my symptoms are getting worse.