That sucks. Hope you get better soon! Do you have a primary care physician or family doctor? They should be able to help you with prescription medication for nausea and also help manage your acid. Are you taking max dose protonic already for example. I would also suggest to get tested for helicobacter pylori.
Sorry to hear of your struggle. Like others already suggested, keeping a diary with your symptoms can help the diagnostic proces. However the symptoms you list are difficult to pinpoint to one specific neurological problem, assuming you already had an MRI of your head, an EMG and a lumbar puncture.
In my experience doctors can sometimes be very good at what they do, but very bad communicators. The way you can best stand up for yourself is to prepare your visit. Write down the questions that you have. It helps if you can clearly articulate what it is that you want from them. But allow yourself some time to think about this question first. Sometimes, what you need has more to do with being taken seriously, or being reassured nothing bad is going on than having a diagnosis. Keep in mind that although modern medicine has come a long way, we still know very little of the intricate processes of the body. Maybe there isn’t a know diagnosis yet that explains your symptoms. This doesn’t mean that your symptoms aren’t real, they absolutely are! A good doctor should in this case be honest and tell you that they just don’t know, and they are out of testing options. If this is the case they should however try to help you manage your symptoms and get your life back on track. Lastly, consider that there are a set of psychosomatic disorders that can give real physical symptoms, but they should only be considered if other diseases are ruled out first. Read up on them, but don’t let a doctor suggest it without having properly gone through the diagnostic process.
I wish you the best of luck and hope you get better!