Prayer is the only way you will ever conquer your doubts. You have to know with a certainty for yourself that the Church is true and you can only know for sure through the confirming power of the Holy Ghost. Pray about it. A ghost will tell you its all real.
Here's how it works:
1. The Church is true.
2. Kneel in humble prayer as ask God if it is.
3. God will tell you it is through the Holy Spirit.
But if you're having trouble getting to #3, just keep repeating #2 and everything will work out because #1 is what it is.
What? God told you the Church isn't true and that you should keep your previously held beliefs? That doesn't make any sense! You must be doing #2 incorrectly. Be brave. Try again.
Huh? You don't think this is a very effective method of determining truth because the conclusion is maintained at all times, even in the cases of the absence of evidence and contradicting evidence? Is that a problem? Should we be worried?