Separation Anxiety - Leave your young toddler with familiar people
Rehearse the separation sessions by leaving your little guy or girl with familiar, trusted people such as family or close friends whom you know will do a good job of taking care of your child. Try doing this for short sessions a few times a week, and then lengthen the time period once your child is able to handle the brief periods of separation. Even if your child were to cry while you are leaving, don't give in to the temptation of returning. Hide behind the door or linger outside the room, someplace from where your child cannot see you.
Be within earshot so that you don't get too anxious yourself. A good caregiver will be able to distract and calm your child down. Again, give this time. Eventually this problem will go away. A few warm-up sessions with a regular sitter are also necessary, for your toddler, the babysitter and yourself.