What causes mediastinal burning sensation and pain?

Hi doctor,

I am a 47-year-old male. I have a very uncomfortable mediastinal burning and aching sensation that comes and goes daily. I had done CT scans on my heart and lungs and the results came back normal. I had an endoscopy, that reported no malignancy but a small hiatal hernia. The symptoms seem to be esophageal related, as after eating I have a lot of pain and pressure in my chest. The pain can be palpated by applying pressure on the area just below my sternum. The burning tingling in my chest is worrying and it does not feel like stomach acid. Sometimes, after eating I get a dry cough that brings up white sticky mucus. Omeprazole has made no difference and I have started regurgitating a small amount of food after eating and feeling nauseous. My stomach is constantly bubbling and throwing up air into my esophagus. A few months back I had an unprovoked PE and I am taking Rivaroxaban for 3 months.

Thank you.