Regurgitation or reflux?

I feel like something is trying to come up all the time. Often burping temporarily relieves it but it comes back straight away. When I do burp I 'vurp' and liquid comes up into the back of my throat. Sometimes it is sour, sometimes it is very sweet (but not a nice sweet),often it tastes like sick. I have a pressure in my chest like I need to burp, vomit or hiccup but it's just there all the time.

I do get the burning in my stomach and pains that are associated with GERD and HH but most of the time antacids stop that.

My question is, is this regurgitation or reflux? Sometimes I get food in my mouth which I know is regurgitation but the feelings I describe above are the main symptom.

I've had the barium swallow and down the have manometry and 24hr ph. What's volume reflux?