People get so tied up in this world that they forget that their real worry and anxiety should be about their life hereafter.
Islam teaches us to change our worry and grief from the matters of this world to the matters of the hereafter. Make your primary worry, the thing that keeps you up at night, What is going to happen me when I die?
This will instantly relieve your worries of this world. It makes the worries of this world manageable. There is a hadith which says that who ever makes his concern with his life the hereafter, Allah will take care of his affairs both in this world, and the hereafter! SubhanAllah!