Finding joy when in pain, finding happiness when you are sorrowful. Do not forget the Word of God gives you the answer.
Sorrowful, yet always rejoicing; poor, yet making many rich; having nothing, and yet possessing everything. (2 Cor 16:10)
In this you greatly rejoice, though now for a little while you may have had to suffer grief in all kinds of trials. These have come so that your faith—of greater worth than gold, which perishes even though refined by fire—may be proved genuine and may result in praise, glory and honor when Jesus Christ is revealed. Though you have not seen him, you love him; and even though you do not see him now, you believe in him and are filled with an inexpressible and glorious joy, for you are receiving the goal of your faith, the salvation of your souls. (1 Peter 1:6–9)