I can't hold it in much longer

Right after we came home from the hospital after having my baby my 2 two year old was diagnosed with RSV. He has been kept in quarantine for over a week now because he's still coughing and now my boyfriend and I are sick with cold symptoms and my almost 2 week old baby is so congested and sneezes alot and is starting to cough a little bit. My boyfriend told me if my newborn gets sick it's all my fault(he's not the bio dad of my 2 year old). I've been trying to keep my hands washed and have had limited contact with my 2 year old but I still have to take care of him too. We've been fighting constantly over little stupid things, he's told me I'm not doing enough for my newborn and that I'm not doing a good job taking care of him but I'm trying so hard. I'm so overwhelmed with everything from being sick my older son being sick and recovering from a c section, constantly having to pump breast milk. Everything between us has changed since coming home with the new baby. He treats me completely different, told me he loves me still but he's just tired of all the little fuck ups I make. Told me he doesn't really care how I feel anymore because I'm an adult and I need to get over it and that his priorities are with the baby only now. And now my baby is getting sick and it's all my fault and idk what to do. I can barely breathe I'm so overwhelmed 😭😔😫