Hi
I am sorry for all you are facing. When I came to the boards 5 years ago I was 28. Like you I had every dx test multiple times,traveled to hospitals out of state,many specialists. So though I know it may not help you are not alone. A few thoughts and I am sorry if you mentioned it.
First though I did not go to Mayo but I did send my records for them to review to see what they thought. You may want to call the neurology dept and ask them about that before you fly out. Also did you state are you being treated right now with any meds or other? I ask because out of all the neuros and other specialists my anestesologist/pain doc gave me insight and direction too. Now for myself I still dont have a why behind my peripheral neuopathy and I do have RSD to. I have other symptoms as you do such as eye problems etc as well. Obviously not knowing the why behind makes it harder to treat.
Ok sorry now to my ?s before you stated you were healthy but can you think of anything even if it was small such as being sick a lot, did you fall,injury,break anything, meds or other you were on?
I wish I could offer more suggestions. I am not an expert like others here on medical but I do know what you are going through the frustration,fear,pain,confusion. On a side note make sure to keep all your records so you can take them to the next apt. Also anything you have tried meds or treatment wise. You may want to keep a diary too of pain and symptoms. Hang in there