I sometimes get something that sounds very similar to what you describe, ExD, though mine doesn't usually last that long - one very bad day (or more commonly, night rather than day, as it often starts late afternoon), then increasingly weak 'aftershocks' for a few days after that.
My stomach (and I do mean stomach, rather than abdomen) feels bloated and painful, and anything that helps me to burp relieves it temporarily, though it doesn't make it go away. Only time does that.
In fact, I have found that precisely because they help me to burp, fizzy drinks do help a bit, though in my case lemonade-type drinks make it worse, but fizzy water helps.
Over time, I have learnt a few other tricks -when the discomfort begins, I stay as upright as I can, and even jog on the spot to try to release any gas that is trapped in my stomach. It can help, and very occasionally even staves off the attack.l
Anything that I eat while suffering from this makes the discomfort more severe. The worst bout I ever had was while away on a break, and though I as already in discomfort, I felt I had to eat out inrestaurant with OH. Huge mistake, resulting in an awful night!
