Be renewed in the [new] spirit of your mind. Having already put off the old man and put on the new man when you believed (Eph 4:21-24), focus on your position in Christ, not on your condition on earth. Walk in Him by the spirit God has given you.
Meditate upon the examples of patient suffering found in His Word. “For whatever things were written before were written for our learning, that we through patience and comfort of the Scriptures might have hope” (Rom. 15:4).
Yield at all times to the work of growth. “…we also rejoice in our sufferings, because we know that suffering produces endurance…endurance, tested character…and tested character, confident hope. And that confident hope never disappoints because God's love floods our hearts through the holy spirit given to us.“ (Rom 5:3-5).
Pray always. “In Whom [Christ] we have boldness and access with confidence by the faith of Him.” (Eph 3:12), therefore “Be anxious for nothing, but in everything by prayer and supplication, with thanksgiving, let your requests be made known to God; and the peace of God which surpasses all understanding will guard your hearts and minds through Christ Jesus” (Phil. 4:6-7).
Know that the Lord will sustain you. Even though our trials or circumstances may continue for a long time, they are temporary insofar as they are producing a weigh of eternal glory the sufferings cannot compare with. But no matter how long they may last, the Lord says, “My grace is sufficient for you” (2 Cor. 12:9).