Key,
Please consider my humble attempt to help!
I don't have much to offer you, other than the assurance that God Himself must be your portion, and He will be your help.
Here's the best I can offer;
I'd strongly recommend that you read this;
THE DOUBTING BELIEVER by OBADIAH SEDGWICK
About the book;
"Am I really a Christian?” At one time or another, all believers encounter periods of doubt regarding the genuineness of their faith. In this book, Puritan pastor Obadiah Sedgwick explores the kinds of doubt that commonly arise in the context of true saving faith, gently guiding the reader through fourteen circumstances likely to produce uncertainty. Using the Bible as a road map, the author helps us navigate away from the rocky shoals of doubt into the safe harbor of assurance.
An excerpt from the book;
"It is well-known to Satan what a serviceable channel faith is for all of our traffic, either for our ship to launch out into duties, or for God’s ship to arrive unto us laden with mercies””and therefore there is no other grace that he assaults as much as he does our faith. If the foundation is weakened or shaken, it has a spreading influence throughout the whole building. A Christian’s faith cannot be wronged without the entire spiritual frame quickly becoming sensible of the wrong and loss."
"If you would make any part of your battle strong, then focus your attention upon anything that contributes to and maintains a spirit of unbelief. It is certainly true that the foundation of your doubts is original sin, but the great pillar that rests upon it is lingering unbelief. All of your staggering, reeling, questioning, and doubting comes directly from your unbelief. O weak believer, this is what prevents you from seeing Christ, the covenant, the promises, and your title! This is what distorts your judgment and misleads it with cunning arguments, so that you cannot discern the full truth of God’s promises, or see the prevailing reasons for persuading yourself that they belong to you."
"'O,’ says the humbled sinner who has a true sight of himself, ‘what a broken state of affairs this is! What an imperfect measure of holiness! My light is dim, and there is a sense of drudgery in all of my duties. My righteousness is defective and my faith is mixed with much unbelief. My prayers contain a great deal of coldness, irreverence, and distraction; and when I have mourned over my sins, I am grieved for not feeling more grief. Thus I hate myself, because I cannot otherwise hate my sins. How then can I stand before God, whose eyes are too pure to behold sin? Will the Lord accept such a person, who discharges his duties so poorly?'"
"You are in God’s divine favor, though you cannot feel it; and although your comfort lies in the feeling of it, yet your happiness is in the being of it. You are saved because God loves you, not because you perceive that love."
You may order a copy here:
http://www.heritagebooks.org/products/the-doubting-believer-sedgewick.html
There are also other books on this topic at the link.