My Son is now 8 years old.Now in studying in a Private school in North Toronto.When he used to go to his preschool, he was quite upset.It seemed like he hated his preschool (or may be its because he missed me!).He used to refuse to have food from there.It took about 4 months to finally adjust to the new environment.He found his new friends and i found him happy again.Some kids are like this .They like to be in the shade of their parents!It takes time for them to adjust...Give them some space and time!