I agree that she overreacted.

I don't think she is OCD either. It almost seems like she's as fed up with you as you are with her and that it's a good thing you guys are moving out and won't be roommates anymore. Toward the end is can get really catty if the roommates don't get a long very well. I'm sure she was not always a bad roommate, but it's become more recent in the last previous months. This happens.

(I have had my fair share of bad roommates too)

The best thing to do is wait out the least and move away and stop contacting her if you can help it. Hopefully you find better living arrangements!