Bloated stomach

Im 14, and my bloating started 8 months ago. It wasnt that bad at the time, but it went away. This month, it has gotten A LOT worse. It NEVER goes away, even when i get up in the morning on an empty stomach, im bloated. Ive been eating very bland foods. The bloating is so unconfortamble, its hard to breath. I had a sonogram and an Upper GI test(drinking the gross stuff), they were both fine. Im not lactose intolerant by the way.

Some background info: When i was younger i had a lot of stomach issues that never got solved. There was a time when i was 8 years old, i was nauseated everyday with stomach pain. The doctor back then, never found anything (except she always said i have a ton of gas), but my symptoms (nausea and pain) just went away after a few months. Now, im 14 and still burp all the time.  I have ton of gas. And now im having bloating. The doctor now will probably do another endoscopy (i had one when i was 8) but i was wondering if anyone knows what this is? Do you think, because i have so much gas, that its being trapped in my stomach or something??

Another symptom ive been having is weird dizziness. It started around the same time when my bloating started 8 months ago. I was thinking maybe they are related. What do you think? thanks, i really appreciate any help.