Probably the most helpful interventions you can offer your baby is to provide plenty of nasal saline (over-the-counter salt water solution available in a spray or dropper).
Also using a bulb syringe
to gently suction the nasal secretions will help your baby to breathe better. A cool mist humidifier
in the bedroom is helpful. Also sleeping a bit upright (eg. In a carseat or swing) is beneficial.