Dd1 was born at 34 weeks by emergency cs, so I have been through what you are going through. Leaving them is the hardest thing to do, especially if they are unsettled. When you are with her take over from the midwives. Take her temp, changer nappies, clothes, bedding anything you can to be part of her routine. Cuddle her while you are expressing so you have extra time with her.

Hopefully it won't be long before she is home, how is she health wise? Are they just waiting for to be able to do all suck feeds in a 24hour period?

Focus on each day, to successfully manage a bf, even for 5 minutes, enjoy the cuddles. Take photos to have at home. When you are home rest, expressing full time is exhausting.

Hope your dd is home soon.