Advice baby is sick.

So I took my 5 week old to the doctor today because she had a cough, congestion, was not drinking her bottles or would only drink 1-2oz (normally takes 4oz), and just wanted to sleep. My daughter was also born at 35 weeks and spent 5 days in NICU. Her doctor then took her temperature and it was 100.5. He told me she had a cold and to give her infant Tylenol. I'm a nervous wreck because all I can think about is pertussis (whooping cough) I mentioned my concern, but her pedi doesn't seem concerned. A little bit of background, my mom and I run a daycare in our home. My daughter and I stay in a closed bedroom up stairs away from the kids. All of our kids are vaccinated, but I'm still concerned. I can't get the vaccine because I am highly allergic so therefore I was unable to get vaccinated. It's now 5am and my baby girl is sleeping in my arms. She has trouble sleeping in her bassinet because she is so congested and when I just fed her she started to cough and gag. I have a cool mist humidifier on and I don't know what else to do. I am so scared and all I can do is cry and panic.