Does anyone know any remedies for a newborn with a cold?

MARCLA
My 4 week old newborn has a cold.. I know there are no medications for newborns but he is having such a hard time breathing. I'm using the saline nose spray and the booger sucker plus a Hamitfier i even put vicks vaper rub in it.. but is there anything else I can do? How long is too long for an infant cold?