I can empathize with you wanting to be home with your baby. I feel so sad everytime I leave my grandkids. I see them several times a week but it just isn't enough. At the same time I realize that they are not my children and they need to be with their mother. And in reality I wouldn't want to have them full time. Still I sometimes miss them so much just after they leave or I leave that I could cry.
I think that attachment is a part of who we are and how we relate to our babies for a purpose. In the far distant past, this attachment was necessary for the babies to survive. We don't need it any longer in most cases to ensure that the baby gets it's physical needs met but it does play a role in getting it's emotional needs met.
At the same time we do have to let go so that they can learn ways to live without us. I would list the positive aspects of you leaving them work.
1. she is getting to spend time and build a close relationship with her father. Many children don't have that opportunity. The "experts" say that the success of a girl's relationship with men is influenced greatly by the quality of their relationship with their father.
2. each of you are learning to live a balanced life during which neither is totally dependent on the other.
3. it appears that your daughter has adapted which is a positive comment on your mothering thus far.
4.Now you have the opportunity to also learn how to adapt to this change. I'm not sure why you feel guilty. Returning to work and leaving your daughter in the care of her father is just the first separation that you'll have.
I do understand feeling sad, even grieving because this is a major change. And being concerned that she is being appropriately cared for is a good concern but you know that she is with her father. Do you have confidence that even if he doesn't parent in the same way that you do that he is able to take good care of her? I would understand the guilt more if she were in a day care setting where you would have little knowledge of or control of how she is being cared for.
I would suggest that it will help if you can find out the source of your guilt. And accept the grief that is natural when you make this major change.
I recognize the pain. I think most mothers have mixed feelings about returning to work. And to state the plain truth. We are attached to our little ones, being with them is pleasurable and satisfying. AT the same time we need to have other experiences just as they do. From your description you returning to work meets the needs of both your baby and you. It sounds like a healthy situation to which you will eventually adjust if you can get rid of the guilt and think positively about it.
I'm sending you encouragement during this difficult transition. And I whole heartedly know how much you miss her. I adopted my daughter as an older child. Perhaps that's why I miss my grandchildren who I've known since birth so much. In my situation I see my longing to be with them as a part of my own need and not theirs. And it is difficult to find a balance in taking care of everyone including ourselves.
M.