In Spanish class we had a test. This guy asked me for the answers; he is an upper classman. I knew it was a sin, and I didn't want to do it, but I did anyway. I feel stupid and hate this blasphemous sin I have committed. Only now did I realize I could have said "no." I really don't like sinning, and when I know I've sinned I get furious. This is the reason: I'm a teenager. I haven't been baptized yet. My father believes in infant baptism, and he hates when I bring up non-Orthodox belief systems. (He is Eastern Orthodox.) He won't let me get baptized. My parents are divorced. He's the only one I can ask and he won't let me. I can't get out of my head that if I die now, before I'm baptized, I will go to hell. It just doesn't seem fair. I need advice I'm stressing so much. This on top of school and sports is like hell on earth. I just want to be a Christian, that's all I want. It's so hard in this situation.
I agree that it is a tough situation. I've run across it before. Legally your father has the right to refuse your religious choices up until you reach majority, which is 18 in most states. Technically, this isn't enforced if the minor is making his choices of his own free-will. From a biblical viewpoint, laws like this are contrary to God's laws and God's laws always takes presidence.
If you were nearby, I would suggest that you come by and get baptized. Attending worship services with fellow Christians would be a bit harder, but it usually can be arranged. But until you can figure out a way to sneak in a hour to get baptized, I would suggest that you pray to God. Tell Him you know you've sinned and that you need to be baptized to become a child of His. Ask Him to help you find a way to be baptized. I'll be praying for the same thing. Knowing our Lord, I'm confident that the opportunity will come up. So put aside your fears and look for an answer, even if it might take a few years to get it accomplished.
Meanwhile, continue studying God's word. Learn all you can so that when the day comes, you are ready. Look at the case of Cornelius in Acts 10. He was a righteous man who prayed to God regularly and did all he was able to do. He had never entered a covenant with God, but God arranged it so that he could meet Peter and become a Christian. What I want you to realize that this all didn't happen in one day. Though it took time, God made sure Cornelius had the opportunity to be saved. The same will be true with you if you continue to put God first in your life.
You've reached the age that you realize that your are responsible for your sins. You can repent of those sins even before you have the past sins washed away. As you learn that you did something wrong, make changes in yourself so that you don't repeat those sins. Thus, think about why you gave in to helping someone cheat on a quiz when you knew it was wrong. What is it that you need to change in yourself so that it ought not to happen again?