Thank you for sharing what is on your heart. I hear gratitude for your brother and for God's kindness to you, and also the burden of sleeplessness. I am praying for you.
It is a wonderful gift when God gives skill and insight to make medicines that help with suffering, and we can thank Him for your brother's brilliance and for any help that comes to those with leg problems and other serious illnesses. Yet true rest is not found in human skill, in wealth, in knowledge, or in any other effort of our own. Those things can be useful, but they cannot give the deep peace your heart needs in the night.
Scripture makes a distinction that may help you. Through the blood of Jesus we can have peace with God, being forgiven and brought from darkness into His kingdom. That is the foundation. Then there is also the peace of God itself, a quietness of heart and mind that guards us even when circumstances are unsettled. Many have the first and have not yet entered into the second. They are still striving, still carrying the weight themselves.
God has promised a rest that remains for His people. It is the rest of trusting completely in what Jesus has already finished on the cross, ceasing from our own works as God ceased from His. We enter that rest by believing, not by trying harder. Faith is the only place where real rest is found. When the mind is stayed on Him and trust is fixed on Him, He keeps the heart in perfect peace. That peace passes understanding, and the world cannot give it and cannot take it away.
In contrast, when we keep looking at problems or at our own ability to solve them, anxiety grows. The heart becomes like a troubled sea that cannot rest. The invitation of Jesus is to come to Him, to walk with Him, to commit your way fully to Him and leave it in His hands. That complete surrender is not a burden, it is rest. It is saying, Lord, this is Yours, I trust You to do what is right and good.
For your sleeplessness, I encourage you to practice this in a simple way. When worry rises, turn your thoughts to the Lord Himself, to His greatness and His care for you. Cast your anxieties on Him, because He watches over you with loving concern. You do not need to have every answer. You can say from the heart, I rest on You. God knows how to keep you, and He wants you to live in peace. Unbelief is what keeps us out of that rest, so ask Him to help you trust Him more fully.
I will pray for you and for your brother.
Father, thank You for Your kindness to this dear one and for the gifts You have given to his brother. We ask You to use all good medical help for Your glory and to bring healing according to Your will to those who suffer. For this one who cannot sleep, grant the gift of rest. Forgive sins through the blood of Jesus and establish peace with You, and then fill the heart with Your peace. Keep the mind stayed on You. Lift the weight of striving and teach what it means to rest in Your finished work. Let Your love and the comfort of Your Spirit abide, and give quiet sleep and a renewed confidence that You will take care of what is entrusted to You. In the name of Jesus we ask this, amen.
May you know that God has ordained peace for you and that He is able to keep you in it as you look to Him.