At this point, if I were you, I would ask to be referred to a GI doctor for testing.
Endoscopy, manometry, etc can answer questions about what is going on inside you.
In the meantime try avoiding gas causing foods, acidic foods, junk foods/sugary foods (and soda!), and over eating if you can since those things mayl make the problem worse - and get yourself some Gas-x.
I'm so sorry you're having such a tough time.
The best thing you can do though is to be your own best advocate!
Don't take a brush off of your concerns, push for a referral and get yourself some answers.
Hang in there...