Regarding your medication not being covered by insurance, I would suggest you find out the manufacturer and see if they offer the medication at a lower price and/or sometimes for free depending on your financial status. Most, if not all companies have what they call an assistance program. Don't automatically think you would not qualify because you may be surprised. Of course, there is paperwork involved.
The psych appt is likely to help with any stress, poor sleep, etc due to gastroparesis (GP). Stress, lack of sleep can cause GP symptoms to worsen or flare up. Several studies have shown that "cognitive behavioral therapy" helped people suffering from IBS or Functional Dyspepsia so a lot of places are trying it with GP patients now.