Poor thing! My sons got sick when they were 7 months old and we put a cool mist humidifier in their room at night (what a difference!) and made sure to put saline drops in their noses at every diaper change (since they're already lying down). That helped keep the congestion moving. We also put infant Vicks (Target brand is the same and MUCH cheaper) on their chests twice a day to keep their chests from getting too congested. From there, lots of rest and TLC.
We left sippy cups full of water in their play area all the time so they could drink when they wanted to, instead of having to ask for it. We found they drank a lot more that way (and still do).
Definitely talk to your pediatrician before using any OTC medications. Mine said that we couldn't use any of them and to stick with the Vicks, humidifier, etc.