Meh, GP's look for the obvious unless they're particularly worried, I'd take that as a reassuring sign myself.
Anyway, no snot, but your nose is blocked? So it could be sinus, it could also be allergy, either of those can leave your throat dry and hoarse. Sinus especially will give you postnasal drip, which when I've had this in the past has left me feeling sore, hoarse and to be honest feeling sick from swallowing all that badness.
If it's allergy related try a mild anti-histamine, you could also try a saline nasal spray for your nose and see if it opens things up a bit. As for your throat, I suspect alot of it is caused by anxiety but it won't harm you to drink a bit more water, fruit juice or whatever.
I suffer from IBS too and if it's affecting your upper GI then you could have acid irritating your throat (you don't even need to be aware of it for that to be happening), though thankfully my sinus problem of many years resolved after an ear infection last year, I also drink far more water than you (2-2.5 litres a day) and I still have the dry throat and hoarse voice which will last for days at a time.
Try to stop worrying about it so much easier said than done I know, you've said you've had these symptoms before, I think in time these will pass too.
Chris