Dear Sister,
Let me share a couple things that I pray will help somewhat. Oddly enough, what I am going to say was initially spoke to me by an atheist several years ago. But it is true regardless of who said it.
You really cannot decide what you are going to believe. Belief does not come by a decision. You did not wake up one morning and "decide" that you were going to believe the gospel, and you cannot in like manner just "decide" you are going to not believe it.
Belief come as a result of the discovery of truth.
One day you discovered that Jesus was Lord, that He died for your sins, and that He rose from the dead. Most people are not looking for this truth when they find it, I doubt you were either. It just kind of sneaks up on them unawares. You might say that the truth finds them. From that point on, they are helpless to the overwhelming integrity of it. God spoke, and it is so. You might say that faith does not come by the efforts of the believer, rather is comes by the integrity of the speaker. God has infinite integrity. We cannot help but believe.
But here is something that might help. Did you know that you could not even believe this in the first place unless He opened your heart and mind to it? That is correct. God has spoken to you! The mere fact that you know that gospel and take this matter seriously tells me, and should tell you, that He has spoken to you and therefore, at some point, you came to believe. If you came to believe, then you are a believer. And people cannot just rationalize that away. Belief is of the heart, not the logical reasoning process. If your were a believer then, you are a believer now. Your mind may be having problems rationalizing things... but that is normal and it will pass. It may take years for your mind to catch up with your heart. That is OK! And even after you understand some of these things, the scripture says not to lean to your understanding of the facts, rather remain in faith and just believe.
I know there are a lot of things in the scriptures that are difficult to understand. Hang in there little sister. You are very special to God, and He loves you with a great love. I can feel His love for you as I write these words! He sees you every moment, knows your fears and sorrow. He understands your doubts and questions. But the answer at this point is to just be faithful. Get in with a good crowd of people who understand and will help. But what will help you the most is to try and help others with questions and doubts that you have already handled yourself. Give and it will be given to you.
PM me if you have any questions, or just to talk.
Love in Him
Didaskalos.