First of all it is not clear whether or not you are at fault and I doubt you'll be able to find someone here who can give you a definite answer. Secondly, there is really no point in quoting German laws in English, if you want to analyse German laws you need to do it in German.

You basically have two choices:

1. You can consult a lawyer for advice and risk having to pay for both the damages and the lawyer or
2. You can pay for the damages

If you are still a student, you can also see whether your AStA also offers legal advice for students (I'm assuming by your username that you either were or are a student here).