Desperate for help!

My baby is soooo congested!! She’s 3 months 1/2. She has bad post nasal drip. I’m already trying the humidifier, saline drops & nose frida & nothing seems to be doing much!! I called her clinic & the nurse told me that since she’s not having a fever, she’s eating well & having wet diapers to treat it at home. It just sucks seeing my little one like this:( she has cough. Earlier she threw up phlegm & also popped some. She breaths quiet it’s just the congestion & cough that stresses me. Is there anything else I can do? She also got congested when she was 1 month 1/2, I don’t understand why so often if she’s EBF which is supposed to be “so good” for her😣 the nurse told me that is normal because it’s their respiratory system to mature from everything around.