Not wanting to let go

I just had my final baby girl 3 months ago, and are finding the idea or being away from her gut wrenching. Our first was a typical first parent, very over protective but she started school this year and is thriving. Our second was a difficult pregnancy and is a high needs child but with our third it was the perfect pregnancy and I feel more connected with her. I'm due to return to work in 3 months and hate the thought of being apart from her. Please help