How can I calm down in this situation?

Basically what happened is that I was called in today by my professor. The professor told me the meeting was about a academic misconduct that had happened. A friend had copied my assignment work and handed it in as her own. What had happened was that I had trouble printing my assignment and my friend had offered to print it for me. I agreed and sent her my project. She instead apparent changed my name to her name on the assignment and handed it in as her own. I had told the professor what had happened and even if I wasn't the one doing the copying, I could still face multiple penalties such as docking 5-10% off my final grade, taking a plagiarism class, suspension from my program, and possible suspension from the school itself. Now I'm panicking and I don't know what to do to calm myself down!