Since what you're coughing up is clear, it might be allergies. Have you tried an antihistamine or decongestant? If that doesn't help and it continues, I would see your doctor.
Hi Lisa, a good old thing is chesse and onion sandwich, but try it with strong chedder and some good red onion, to give some extra strength add some sliced garlic, the best one is just before bed, this will then cut into your mucus and brake it down.
Good Luck