3 month old is sick

Ally • Expecting a baby girl in December!!! 🎀
My daughter was born December 14th and has a cold. (My son who is in preschool got it than gave it to her) I took her to the doctors yesterday and she said just use the nasal aspirator and a cool mist vaporizer. (I feel like that was a waste of my time) is there any other suggestions out there? My daughter is breast fed and can't even really eat because her nose is so clogged. I feel so bad for her.