Hope you are still doing better. How long is the balloon stretch likely to help? I haven't run across that technique in my reading. Cleveland Clinic's Motility Clinic has a lot of articles as well as some research from Mayo I found through various searches and Pubmed.gov site- google for exact address, if want to read journal articles. Cleveland Clinic writes about a surgery technique where they cut just above pyloric valve. They use that if diet and meds aren't sufficient.
Unless you can find some way to control pain without opiates you will possibly not be able to get much better, as that may be the cause. Anticolenergic meds need to be decreased/eliminated when possible is what I gather from readings. I have taken a lot over adult life and take a medium amount of antihistimines, asthma and anxiety and depression meds now. I am not sure I can take less. Will be trying.