Thanks for using health care magic for posting your query.
I have gone through your given history in detail.
Your depot medications may not have much to do with your bulge and on and off back ache and gas pains especially when you have stopped your depot 6 months back.
You can stay calm until you visit your doctor who can ultra sound
you to see the nature of the bulge.
Hope I am able to answer your concerns.
If you have any further query, I would be glad to help you.
In future if you wish to contact me directly, you can use the below mentioned link:
Wish you good health,
Dr. Srikanth Reddy M.D.