Would I need surgery? What's wrong with me? GERD, ulcers, polyps?

Only a doctor who has examined you in person will be able to give you an accurate diagnosis, but it doesn't sound like ulcers or polyps to me. GERD is a possibility, but that typically presents with pain (note the "typically".. everyone's symptoms can be different!). Other things to look at would be low gastric motility (gastroparesis) or low LES tone, both of which can occur for several different reasons. Did you get an EGD or barium swallow done at the gastroenterologist's office? If you feel like your current GE isn't taking you seriously, ask your parents to take you to another one.