Chatterbox: Down to Earth

HELP ME!!!!!!!!!!

Please help me, I have a huge problem! I have this one "friend" at school, she was nice to me last year, but this year she changed soooo much! She's being someone else, someone completely different. I feel like I don't know her anymore!!!! I really want to talk to her about it, to yell and scream! To throw all my feeling out at her! But I can't do it! When I want to speak, I am scared, and I don't want to make her really mad even though she mad me mad! I'm just so scared! What should I do? I need to talk to her something about how I feel, and possibly end our friendship if that has to happen, but I've never had friendship problems like this! I need help!