Hey. I have exact same symptoms. Tremors/vibrating when waking up or they are waking me up, not sure.
My story started when I was dizzy and stomach pains. I went to the doctor and they put me on a proton pump inhibitor (strong antacid). The drug made me lose weight and feel terrible and constipated, it felt like I had malnutrition. I stopped the drug and went to see a natropath.
My Natropath said I have neurotoxins in my system. He put me on a liver detox, that is when the trembling started because the toxins were being pushed out of my liver. Toxins are meant to exit the system via bowels or urine, my bowels were blocked up because I was on the proton pump inhibitor. Instead of going out my bowels the toxins went into my blood and then into nervous system. I ended up in hospital with hyper reflexivity, for example tap my knee and my whole body would go crazy. The doctors had no idea what was going on even though i explained about the detox.
I am continuing my detox and hope that the toxins will exit my system eventually. Things are certainly improving. I believe the reason people feel relief after going on celery juice is because it is a powerful detox. But don't make the same mistake as my natropath, make sure your bowels are clear before going on detox or your symptoms will get worse. A nice gentle way to detox is to go on 'The Liver Detox Diet', this is a book.
I too have been to multiple doctors and specialists and had dozens of blood, stool and urine tests. Nothing showed as being wrong, and they put it down to anxiety. Anxiety is certainly a trigger to it getting worse but there is more you can do to settle your symptoms.