What could this be?? Desperate


This is a long shot but I’ve had a stomach condition for almost 3 years but doctors don’t know what it is. I constantly feel nauseous to some degree never any pain or bloating or diareah just a feeling of nausea. I’ve had a stool test, endoscopy, blood test, ultrasound seen a dietitian etc but no answers. I don’t don’t know if It’s any constellation but I am unable to burp like it comes to my throat and just gurgles I can’t physically burp and haven’t thrown up in about 14 years or so. I’m desperate it affected my mental health for ages I got acrophobic and I struggle daily. Any ideas would be appreciated