Finally I asked my Gastroenterologist to send me for a Gastric Emptying Study. She was reluctant because it's uncommon for someone my age to have Gastroparesis, but in the end agreed to send me for the test.
At the study I had to eat scrambled eggs and toast with barium and then lay still for 2 hours while my stomach was x-rayed periodically.
When my Gastroenterologist told me this I was overwhelmed with relief. For the first time in years I didn't have to try to convince doctors that my stomach pain and nausea wasn't psychological! When I went to the ER with stomach pain and vomiting, I no longer had to be drilled about my level of stress or if I like the appearance of my body. I could actually start taking a medication to treat my problem!!