I'm I just being anxious, or do you think something actually happened to my penpal?

I wouldn't worry about it too much right now, she's probably just busy. If she is nice like you say she is then most likely she won't just blow you off like that. She must have a good reason. Also from what I can tell by answering all your questions for a while you don't seem like the type that would do anything bad to put her off, I'm sure it wasn't you. Wait a bit more before you start worrying about it. That's my opinion anyway. :)