Loaning money, a lot of money like this, can be very tricky between friends, depending on the friendship.

Can you get your money back on the hotel, or is it non-refundable?

I would end this friendship. It sounds like a one-way street on your end only. She doesn't initiate contact, and she starts arguments when she has no ground to stand on, making it your fault, when it's hers to own.

She owes you money, and rightfully, you are asking her to pay you back.

If you can, I would cancel the concert and hotel plans and demand the money back. She is not a good friend for you.

There is no sense in asking WHY someone is the way they are. This is who she is. She is showing her true colors, so believe it. This is not how you would behave or treat a friend, and you don't deserve this kind of behavior and treatment. That's my two cents.