My professer went balistic when some of us "plagerized" our homework? I dont wanna get a permanent record. Help me?

My teacher was very angry and hostile at some of us for "plagiarizing" our essay. I didn't plagerized. She said she gave me a 0 because I copied and pasted my work and called me lazy. I wrote soem sentences not copy and paste it. She told me thag doesn't matter and it's still plagiarizing and this may be on my record for college if it happens again. Luckily she didn't drop us from the class and giving us another chance. This is the first time happening to me. We have another essay test comming and I will prove to her that I don't plagerized. She told me it it happens again, she is dropping me from the class and I'll get expelled from class and even if I take the class over again, that's not going to go away. I just hate upsetting my teachers and my dream might be over. I can't tell my parents because they will be hurt and disapointed and I know how they are.