No, it isn't wrong for you to ask God to bring healing to your body and take away your pain. Chronic pain is a terrible burden, and the Bible encourages us to bring all our burdens to God in prayer.
But if your pain stays with you, I urge you not to get angry with God or turn away from Him in bitterness or disappointment. Instead, I pray that your pain will cause you to turn toward God and draw closer to Him, so you can discover His strength and presence. In spite of your present feelings about Him, God has not abandoned you; He loves you and wants to encourage you. The Bible's promise is true: "The Lord is near to all who call on him, to all who call on him in truth" (Psalm 145:18).
Think of it this way. In your letter, you mentioned that you are married, and although your wife can't take away your pain, her presence has been a source of great comfort and encouragement to you. In a similar way, knowing that God cares for you and is constantly with you will bring you great comfort and encouragement.
Bring your burdens -- including your pain -- to Jesus, and ask Him to encourage you and help you keep your eyes on eternity. The Bible says, "Cast your cares on the Lord and he will sustain you; he will never let the righteous fall" (Psalm 55:22).