What If the Sin Is Too Great To Confess?

I was just looking around at CAF and I saw a thread called "Websites for battling impurity" and I think some of their advice if what I need to heed to. Mostly my sins are sexual and they told me that going to confessional is the way to be forgiven for mortal sins. I have never gone to Confessional and I don't know what I am supposed to do. I am still in RCIA and learning about the faith. My two questions are this: How do I confess in Confessional and what if the sin is to great and disgusting to admit to? I have done so many sexually disgusting things and I feel like anyone who I would tell would think I am a bad person. I think they would hate me If they would know the type of things I have done? I have also engaged in illegal activity(I was never caught for most of it) will the priest tell the police what I have done? Please answer my question I would really like to know.

Also If anybody has any prayers to battle impurity I would like to hear them. I need them desperately. Thankyou.