I went through this about a year ago. It lasted about three months and went away as quick and innocuous as it came on. It was like when you yawn and you can't get just that last 5%. Like when you need to do the breathe in so hard your chest puffs out thing, but you just can't get that last little bit. If it's the same thing, mine went away after a short period. Can't give you any helpful hints or anything!! But Jimmylegs also had described having this in the same fashion; came on, stuck around for a bit, took off. Hopefully yours does that also.