Many children strongly prefer one parent over every other person in the world for a brief period of time. Usually, they prefer their mothers for a period (ranging in length from approximately one month to several months) during the later part of their first year. During this particular time, her desire for you is especially intense, as she is in the midst of a developmental phase characterized by separation anxiety.
Often after children grow out of this stage, they will prefer their fathers over everyone else on the face of the earth. Generally the period they attach to their fathers is shorter than the period when only their mothers can make the world a better place.
Right now this all seems very difficult, but it will pass. One day, in what I am afraid is the very near future; your daughter will be a well-adjusted adolescent. When she skips out the door with a casual, “Bye, Mom,” you’ll remember the time when you were the center of her world and all the tiredness and frustration you now feel will seem a small price to pay.