Returning to work :(

I have been on maternity leave for 15 weeks and this is my last week. I went into work today for a half day to ease back in and it was awful. I missed my baby, I didn’t feel focused on my job, I worried about pumping and whether she would eat well enough without me. But mostly I worry because someone told me that 4-6 months age is when babies “attach” to specific people and caregivers and I’m so sad and scared that she will attach to a nanny or grandparent and that they will develop the special relationship that I want to have with my daughter. I want to see all her milestones and know everything about her. She is changing so fast I feel like I’m going to miss it being back at work. Any words of encouragement/advice from those who have returned to work?