Not coping

I’m sorry you feel this way. You are doing everything in your power for both your babies. I know it’s hard but your NICU baby has the most well trained, expensive baby sitters. It’s so hard to feel like you’re not doing enough, but you are doing more than could expected of any mother. Take your time to recover with your son at home and maybe visit at night after he goes to bed. You can see if your NICU has a camera so you can feel like you’re in two places in once. I only had one child in the NICU to handle but it was 6 months of traveling so I get that feeling. If you need someone to talk to, feel free to message me. Recover yourself first mama, no use to anyone if you get an infection

You are not failing. There is only so much you can do. I would say if your son is at nursery, you can use that time to go and stay with your little girl. And then dedicate evenings to spend time with your son. Over the weekends, when your partner is back, decide on a conquer.
Ultimately, reach out to family and friends, talk to your HV, and see if there is any additional support for you.
You are doing great, and all nurses working there understand it! There is no need to feel guilty. Ultimately, she is taken care off and your son is happy and healthy. That is all you can ask for at the moment. Once she is big enough at home, you will be able to dedicate time for bonding and establishing a set routine.

This was me this summer. Baby was in the NICU while my 3 year old was at home. They didn't allow children in the NICU so I needed a sitter when I'd go for a visit. We leaned a lot on family and are blessed to have my folks close by. Something another NICU mommy said was to not beat myself up so much when I couldn't visit or could only sit for a short period. Which is easier said than done, I know. I'm sorry you're going through this. You and your little warrior are in my thoughts.

I had my twins in January at 32 weeks and also have a 3 year old at home. I understand the struggle! I was sick for a few days and couldn't visit, and it was the worst feeling to be apart from my babies. On days when I couldn't visit I always called the nurses for an update and that helped a little. Sometimes we visited at night after my 3 year old went to bed and had someone sit in the house in case he woke up. It also got a little easier to visit when I could drive myself and my c section pain was less. It is hard and what you're feeling is totally normal! Mine just came home a week ago and are finally just like regular newborns at home. Just remind yourself that you WILL get through it and be together at home soon, even though it feels like it takes forever!