I got the same thing I feel the air going through my throat or mouth and it burns I have gases and blurping too. Its impacting my mental state a lot. Its like mouth breathing but with the mouth closed as trying to get proper oral posture, horrible. 

Anyone got a solution, advices ? 

Are you experiencing such issues only after starting mewing?

@freddie @hamiddkhnn  It's hard to imagine belching being caused by nose breathing. I thought it was caused by swallowing air, which is a problem I have faced while learning a proper mew push swallow. One thing that has helped me, is after I have "pitched" the saliva passed by tongue and towards the back of my throat, I really make sure to push the back of my tongue up when swallowing. This seems to prevent any air from going down.