My daughter started preschool 3 months ago. Ever since her behavior has changed. She seems to be regressing. More clingy, more tantrums than ever and very needy and screaming for a very long time if she doesn't get her way. Before all this she was very independant. Now she's always asking for hugs and kisses and can't sleep without turning the vent on next to her room. I'm so exhausted. What should I do and is this normal? How long will this last?