Laura, do you live with your mum still? If so, look at moving out, because that will make things easier.
I had some horrible arguments with my mother 12 months ago, but that was because I was out of work, and she had stopped taking her antidepressants, a very bad combination. It resulted in my spending Christmas with my best friend's family, and was a deciding factor in my moving 30 miles away. Having put some space between us (and my mum having gone back on the pills) has made things a hell of a lot easier.
As others have said, I think it was simply a case of you being a convenient person to yell at because of stress. Give your mum the time to calm down, and then do something together, and try to discuss why she reacted the way she did. Hopefully, once she's calmed down, she'll see that she was being a little irrational and apologise for it.