I've had similar for 3 months and its snowballed into some real anxiety problems.
I'm pretty sure it was some sort of acid reflux. I was getting it in my stomach but then that went and the throat went pretty much like yours.It took about 2 months to get better but still now its not 100% and i still have a phlegm or something in my throat but thats because i started eating poorly again.
When i was eating healthily and taking the omeprazole it did just about go.