First day of school and internship

My heart is aching.  Dropping Allie off today was the most horrific thing I have ever had to do.  She cried out Mommy Mommy..  Oh my heart just sank.  Everyone can tell me that it is what good for her, she will grow, it will help her with blah blah blah.  I don't feel good about it, I don't like it and I could not wait to get there to pick her up.  I know that this feeling will not get better.  She did great, don't get me wrong, loved playing but when she saw me I could tell it was time to go home.