What Causes Constant Urge To Swallow Saliva?

I always feel the urge to swallow (my own saliva). Usually, when people get extremely nervous, they swallow/gulp- but this out of control gulping happens to me ALL the time, even when I m completely relaxed, all by myself. I am a singer, and during the middle of a song, I will have to gulp. (I will try to hold it off as long as possible, but my throat ends up automatically doing it anyway, leading to a very awkward pause in the song. Not good.) It also happens when I m just talking, on a day to day basis, and even when I m not even saying anything. It only happens when I think about it, though. When I don t think about it, I don t even notice if it is happening or not, but when I do think about it, that s when the gulping starts. My throat starts getting dry as well, and I go about 10-15 seconds between gulps. I understand that everyone gulps sometimes, but this has gotten out of hand. People think I m extremely nervous when I m not, because of the gulping, and it s just plain embarassing when talking to people. I have tried proper breathing techniques, and drinking lots of water to keep my throat hydrated. Nothing works. Any advice would be welcomed! Thanks