Acid reflux and heartburn concern

Hey everyone,
So I've never been diagnosed by a doctor with having acid reflux, but I am 95% sure I do have it. Difficult swallowing, occasional regurgitation, sour taste in mouth, all the symptoms. I've had these symptoms for about 3 years (give or take). What's concerning me though is whats happening in my stomach. Lately I have dull sharp pain behind my heart. At first I thought it was heart issues but then learned it could be from indegestion and heartburn. I've also noticed my entire digestive tract just seems to be off. Constant rumbling and slight pain in my abdominal, really gassy, soft stool, (sorry to go into detail). But when should I be really worrisome though? Should I be concerned about possible stomach or esopageal cancer? Barrots esaphagous? Feedback would be appriciated

(IMO), I would start with diet changes and see if that helps, then it might be a good idea to get some testing done.