My baby has a bad chest & cough, not clearing up after 5 weeks. Anyone have a magic wand?

She's been on 2 sets of antibiotics, ventolin, steriods and atrovent inhaler. I put a cold mist humidifier in her room. I thought it might of helped, but doc said probably wouldn't so stopped... can anyone give any advice on what else I can try. She's sick in the morning coughing up phlegm and wakes throughout the night. She's been poorly so long, just want her better :-(