Have you made personal success in a chosen field the only barometer of how God is working in your life? If so, you have a very shallow view of God.
I'll give you a hint. Once you come to faith in the Lord, the goal of your life is no longer having your personal dreams or goals met. Real faith, real religion, is aligning your goals with the goals of the Father. And the goal of the Father is to bring every man, woman and child on the face of the Earth to their knees before their Lord and savior Jesus Christ.
What did Jesus tell the rich young man what he must do to inherit eternal life? Did he say, go into the City, spend all of your money on yourself and life a self-actualizing life full of contentment? ... No. He said, sell all of your possessions, give it to the poor and then come and follow me. And the young man went away sad, because he had many possessions. And I'll bet you could say he had many plans as well.
(
Matthew 19:16-28)
Have you ever taken the time to consider what God's will for your life is, without simply telling Him what it is you want to do and expecting Him to give it to you? You are right that the Bible tells us that faith like a mustard seed could move a mountain. That whatever we ask for God will give it to us. But what I think is telling is that of all the people in the Bible, including those who lived and walked with Jesus, I don't read any stories about mountains getting up and moving into the sea... So if those men, who are the men entrusted with carrying the faith into future generations after Jesus died, didn't have that kind of faith, then what makes you think that you do? And why do you think that somehow you have been without sin long enough to somehow justify God giving you something?
The fact of the matter is, my man, that God doesn't
owe you anything and God isn't going to give into each of our selfish desires simply because we claim to believe in Him. If that was how it worked, wouldn't the world be in utter chaos? I'm reminded on the scene in Bruce Almighty where Jim Carey, as God, simply responds "Yes." to all prayer requests in his "holy inbox". What happens the next day? Everything is so totally screwed up because people's individual wishes are not cohesive with everyone else. If I ask for something totally contrary to what you ask for, and our wishes intersect in some way, how would God give us both things? You can't have every team in the league win the championship, you know? It just doesn't work that way.
God is not subject to our will. We are subject to His. And if you think you are supposed to be a writer and if that's God's plan as well; then so be it. More power to you and God will certainly be giving you those things all in good time. But if that's not God's plan for your life then you need to be open to idea that what God wants for you is better than what you want for you. (Father knows best, right?) And if you are losing faith simply because God isn't granting your wishing in a manner that is fast enough for you, then whose fault is that? .... It's not God's.