You cannot allow circumstances to make you sad. You cannot allow them to make you mad.
You can rejoice that you are a child of God. You can find joy and happiness in the grace of God and in the love of Jesus Christ.
You can be glad.
If you open your mind and heart to receive the Light of Christ and humbly follow the Savior, you will receive more light.
Line upon line, here a little and there a little, you will gather more light and truth into your souls until darkness has been banished from your life.