Hi, i've been having this choking sensation in my throat for a while now, feels like undigested food stuck in my throat and refusing to go down, sometimes, when i swallow continuously, it seems to go past it and it feels like i'm gagging. other times, when i finally belch some air out, it seems to get better. when i sleep, it sometimes makes me find it difficult to breath while lying down, and once i really struggled in my sleep, which really got me scared. Is this acid reflux, or something else?