The symptoms you are suffering from are mostly functional and a psychiatrist or psychologist opinion may be valuable to find underlying stressors.
Some sort of Tricyclic antidepressants may help you because of their effect on the nervous system of the gut and help your symptoms for which you will need a prescription.
CECT thorax with upper abdomen can help evaluate the extent of the hiatal hernia and help determine a need for surgery.
Next Steps
You can get further evaluation done but try and relax and learn to ignore these symptoms as normal. Investigations might not find any cause which can be corrected with surgery, even if we confirm something like the hiatal hernia, the symptoms are atypical and might not resolve with surgery.
Health Tips
Your BMI is also on the higher side and daily exercise and losing weight might also help with the symptom relief. Besides don't lie down for around an hour after a meal and sleep in a propped up position.