Hot water bottle,or warm towel there. Try lying on your tummy face down , yeah ouch! Worse come to worse, try this maneuver. Take your right ARM , put it over the top of your head and try to grab your left ear. The shifting of your diaphragm will sometimes bring that bubble out. Go for a walk out in the beautiful sunlight, if you belch and dart outside it don't mean no never mind. Do knee bends, kill two birds with one stone, get the gas bubblesout and you've got some exercise in. And keep saying through cleanched teeth, THIS TOO SHALL PASS! and maybe it will!