4month old w/nasal congestion

FTM to a 4month old. Baby girl has been so congested for the past week, feeds and sleep have been terrible. I can hear her congestion while she breathes and everything i have done so far hasn't worked much. Husband and I are also recovering from a flu and the broken sleep isn't helping my headache!!

I've tried saline drops, nosefrida suction, humidifier in the room, steamy shower, warm compress on the sinuses. Nosefrida doesnt get anything really.

Pediatricians office doesnt have any other suggestions. How long will this go on for and what else can I do to make my baby feel better?