You may want to ask your doc to check for problems stemming from the presence of H. pylori. Many with gastritis resulting from H. pylori say they 'never feel full.' Upper R-side pain through to the back might indicate gallbladder issues, but can also be related to gastritis in some individuals.
Also check to see if the Depo might be contributing to the symptoms you're experiencing.
I think hunger is a side effect of Depo but after being on it for nine months I would think any side effects would have occurred earlier than just the past few weeks.
Have you been tested for thyroid disease? Some of the symptoms you describe are those of hyperthyroidism such as hunger pangs and weight loss and stomach discomfort.