I have had the same exact symptoms, as well as ringing in my ears for about 3 years now and I am also NOT diabetic. First they said it was my gallbladder because I had alot of vomitting, and had gallstones that showed up on a CT scan, so they removed my gallbladder. After about 3 months I continued to have the same symptoms so then they said it was severe reflux or (GERD) and put me on medication. The "reflux" especially chest pain contined and I had a Nissen Fundoplication this past March to correct this. If they suggest this surgery DO NOT do it. It has only made the nausea, fullness, and gas/bloating 100 times worse and now I can't belch or pass gas as effectively as before the procedure and I can no longer vomit due to the creation of a one-way valve into my stomach. About a half-hour or so after a regular meal, even very, very small portions, I have chest pain, stomach pain (from the gas), and I am bloated to the point where I feel (and look) like I am about 6-8 months pregnant. I can lose or gain up to 15 pounds in the same week depending on if I eat solid food or not, and if my stomach decides to empty or not. Eventually when my stomach does decide to empty I have unpredictably severe diarrhea with a lot of lower abdominal pain until everything passes. Unfortunately I am managing the exact same way you are. Most days I just have Gatorade or flavored water like Propel, but eventually I get hungry, eat solid foods, and suffer. This cycle never ends, it just continues on and on.

I have been told that the only thing left to do would be a gasgtric pacemaker, which my insurance won't cover until the "official" gastroparesis diagnosis has been confirmed for 1 year, and all other methods have failed, i.e. medications like Reglan,Domperidone, and anti-reflux surgery. This won't be until November for me and if I do decide to have the pacemaker, I have to travel about 2-1/2 hours away from my home and family to have it done. Since there are no guarantees with this procedure either I'm still not certain what to do. It is a real challenge living this way. I haven't been able to return to work since last November and have no disability payments coming in, so my family is struggling as well. I guess all we can do is support each other, pray, and hang in there hoping for a better tomorrow.
Good luck to you!