My baby is experiencing the same thing. Her breathing was so scary last night I took her to the hospital. I was told to give her saline drops to try to flush it out. Hopefully she'll feel better soon.
my baby girl was super congested during her first week, I was worried. I was told to just let it take its course. it's normal. I have a cold must humidifier that I use but that's about it. She is 2 weeks old now and she is no longer congested. Not the best advice but that's just my experience