Newborn with Covid

My newborn (12 days old) has Covid. She was last one in the home to become symptomatic. She had a very mild cough/sneezing starting a week ago. Around last Wednesday (5 days ago), she had a more prominent cough/sneezing/congestion.

She saw the doctor last Monday for a weight check and she appeared fine at the time, lungs were clear, etc. All they said to look for were signs of dehydration and respiratory distress.

She doesn't have a fever. Her temperature has been a steady 99.0-99.6. However, she's just not improving at all. Her symptoms are only worsening. I have the cool mist humidifier going and I use saline drops and suction her nose twice a day (I know using it more can make things worse). However, last night she was up every few minutes because of her congestion, and when I tried suctioning her nose I got literally nothing out. 😩

I feel like I need to take her back to the doctor, but I also feel like they can't do anything. Thoughts?