How can I be a christian again?

I was raised a christian, but I met one of my best friends through school, she swears and talks about very inapropriate things, I used to be disgusted, but after some time, I talked that way too, I searched things on youtube, and printed things out to worship over, my grandmother found a sheet i printed about something very disgusting, she was very upset, but promsied not to tell anyone, I'm npt able to be around her anymore, is it possible to go back to being a innocent christian girl, and get those stories and images out of my mind? please help me! I want to stand out and be obnoxious, but I want to be a christian, and still be a regular teen, someone help me!