That is so cruel! It's a terrible feeling to be victimized. But I am glad they didn't get your car.
How much is the window replacement? Can you all buy one at a salvage yard and your BF put it in? You can drive it without the window, and that is a good thing.
No, life isn't "fair." People act mean to others and are disrespectful. Yes, you were human and left something on the seat. I'm glad you were there to be injured too.
I hope you are working through your anger...it's not good to feel such rage. I've always said it's not what we go through but how we go through it. The situations change, but how we protect ourselves, how we respond rather that react is what is important for our own health.
What type of outlet do you have to release this stress chemical built up right now? Do you play any sports or do anything that is active? That would be a good thing to do right now, and then find some time to think about it and then NOT think about it. Give yourself an alloted time limit to just think about this and all that goes with it, and at the end of the time limit tell yourself you aren't going to let it dwell in your mind. You can always give it more scheduled time later on, though.
Be good to yourself. It isn't your fault. It is something that happened. (((hugs))) TC