hi, i think you should have tests for crohns disease, the burning sensation in your eyes would be from inflammation in your digestive system, plus the mouth ulcers are usually a sign of inflammatory bowl disease, i would suggest a colonoscopy for your large intestine and an ultrasound for your small intestine, that would definitely give you the answers your looking for, good luck.
Can you describe these mouth ulcers a bit more? Do you also have white coated tongue or mouth mucosa? It is very unlikely that acid would cause ulcers in the mouth. If this was the cause, than you'd also have ulcers in esophagus, hard swallowing and a lot of pain.