The Annex was forced to go into hiding. While the Annex are hiding, the Nazis are trying to find any jews hiding. They were forced to go into hiding from Margot getting called up, and decided to just go to the secret Annex for 2 years.
The Annex was caused to worry about rats invading the Annex. The rats also caused a shortage in the Annex's food supply. Resulting in the Annex trying to conserve the food they still have.
Anne has begun to experience depression. The depression is increased from the ongoing events outside the annex. Also from worrying about her family that is not in the protection of the Annex.