What do you do for a 5 month old that has a cough and very stopped up?

Kaci
My poor baby is sick for the first time and it just kills me. He's got a cough and what's really bothering him is he's SO stopped up that he can't really breath out of his nose. He can't stay asleep very long without waking up.. It will probably be another all nighter for me again tonight. Any suggestions? :(