Take her to an allergist. Explain the severity of her systems so that you can get in right away.
My granddaughter has allergies and sees an allergist. Her pediatrician referred her to an allergist right away when she was less than a year old.
When she was a toddler and her general health was compromised as it sounds like is happening with your daughters he prescribed an antibiotic as well as an antihistamine that works better than over the counter ones. We had already tried children's Clariton. She also has a nasal spray. The allergist did a few skin pricks and said that she was allergic to milk, peanuts, soy, eggs. Her health improved once we stopped giving her those foods. She was having frequent asthma attacks and those subsided as well.
It sounds like your daughters are very uncomfortable and the congested cough and sad demeanor mean that they do need treatment right away. If their breating has become shallow or it looks like they're struggling to breathe they may have asthma which can be life threatening if not promptly treated.
Having babies this sick is scary. They do need a diagnosis and treatment as soon as possible. This is the allergy season for pollens. I just read an article that said there are many more children than adults with allergies because most allergies that start during childhood go away as the child grows. My granddaughter can now drink milk, eat eggs and bread. She still has to completely stay away from peanuts and peanut allergies are one of those that often continues into adulthood.
Your babies will be and feel better and so will you once you know what is happening and how to treat it. It's difficult for most of us to see our children suffering and not be able to help them. I'm glad that you're holding them more than usual. They need that extra support.