When you walk into a brightly lit room from darkness you squint your eyes.
When you wake up after a refreshing nap you still feel little groggy the first couple seconds.
In the same manner, when joy peeks in after what seemed like an eternity of grief, when relief comes in after an eternity of oppression- it is natural to be scared initially. Its okay if your initial reaction is that fear and not gratitude. It really is- because the years of tears and pain made your entire existance learn to anticipate only worse. It will be sometime before it reverses itself. So its okay, because birds raised in cages are afraid to fly.