So sorry you're having so much trouble finding a diet that works for you. I'm sure it must be frustrating. As a GERD sufferer, I can understand looking around a restaurant and seeing people eating onion blossoms and drinking margaritas and knowing they don't have to worry about what they put into their stomach (well, really they should, but they don't HAVE to).
From what I'm reading here on the forum (mainly from GerberDaisy, who suffers from LPR) there isn't a clearcut answer, and that the Nissen Fundoplication surgery doesn't necessarily work for it. I don't understand how it couldn't help, though. I had the surgery although it wasn't positive that it could help me. My problem was uncontrolled asthma, and my GERD numbers weren't all that high. My doctors (family and asthma) kept nudging me towards the surgery, and although I wasn't a classic case, my GI doc referred me to a surgeon, and from there I made the decision to give it a try. It has made a tremendous difference. I had the surgery 5 months ago, and my lungs are clear for the first time in four years.
Post surgery, you still need to watch what you eat at the beginning. My stomach is reactive, so I still have to watch all the time. I pretty much eat whatever I want until I have a stomach upset, then go to more careful choices. (No onion blossoms or margaritas, though! LOL) However, it's HUGE improvement over what I was going through, and I've been able to reduce my use of steroids, which were causing some severe symptoms (I have some residual permanent damage, but at least it won't damage my body further), which is really important for my health. It's great to be GERD free!
I would suggest one thing, though. The less you fight your situation, and consider it "hell on earth", the more difficult it will be to be a happy person. Acceptance of your situation will make everything seem less horrible. If you can look for ways to introduce some more interesting choices into your diet (you can try things, and if they don't bother you, add them in). Look for the things you have to be grateful for in your life situation. Try not to focus on the negative. That only makes it harder to find happiness! You CAN have LPR, and stay positive! That's not to say that you won't continue to seek out answers. Hopefully GerberDaisy will respond to your post. You might want to do a Google Custom Search (located in the top right corner of this page) and look for her posts. She's been exploring surgical options, because of the same issues you're experiencing.
Welcome to the GERD forum! There are lots of supportive and informed members here, who will provide you with lots of information and encouragement!
Take care and stay positive!