Your heart burns for this dream, and you say it is never too late. That is true: God's calling resounds across all ages, and the Scripture foresaw that He would justify the Gentiles by faith, preaching the gospel beforehand to Abraham long before the Law. So time is no barrier to His purposes. But I urge you to examine closely what you call a dream. The present life is a sleep, and all its honors are no different from visions of the night. A man becomes consul and for a day shouts echo his name, yet when night falls, he has nothing more than the one who dreamed the same honor while asleep. If this dream job is pursued for self-fulfillment, for the fleeting pleasure of recognition or the comfort it might bring, then you are making provision for the flesh to fulfill its lusts, and such striving fans a fever, not a cure.
Do not hear me as one who despises labor or the desire to contribute. The apostle bids us work with our hands and to supply our needs with quiet industry. But the heart's desire that God blesses is not the craving for a specific title or position; it is the longing to be counted worthy of His calling, to fulfill every desire of goodness and every work of faith with power. When you set your mind always on God, remembering Him in every thought, all things become endurable, and no earthly ambition can master you. The dream that endures is to be well-pleasing to Him, to use whatever station He grants for the health of your soul and the building up of Christ's body.
Now your children are grown, and you have more time. This is a season of divine opportunity. But I bid you, do not run with a blazing torch after a particular role as though it alone could satisfy. Pour out that energy in prayer and service where you are. If God opens the door to the work you imagine, enter it with thanksgiving, doing all for His glory and not for the vanity of human praise. If He withholds it, do not despair; He may be sparing you from a weight that would kindle pride or neglect of things eternal. It is never too late to abandon the perishable for the imperishable, to store up treasure in heaven rather than chase shadows on earth.