Hello and welcome to MedHelp's forums. Issues are often not in our imagination even if not caused by a direct disorder. We do not doubt you suffer from the symptoms you are listing. A one time happening of something, however, is often written off by chance and not something to be terribly concerned about. Perhaps keeping a journal of these types of things will help you track it better. Do you have a family doctor that you see? Then you can present that information to your parents and then your doctor for guidance.
An area to look into is Gerd. https://www.webmd.com/heartburn-gerd/guide/reflux-disease-gerd-1. Let us know what you think.
It is not possible to diagnose from here, because some of your symptoms are likely just in your imagination, since they only occurred once. You should see a doctor for a diagnosis because stomach issues can get worse if not treated.