I don't mean to be unsympathetic here, in fact quite the reverse because what you are going through seems horrible, but it really irks me that so many people on here seem to make the same basic mistake.
Because, for some reason that I can't even begin to comprehend, you convince yourselves that you can't tell your parents the truth, you repress your feelings, and that just aint healthy! Result - the angst and suffering finds all sorts of other ways out and you become depressed or anorexic or bulimic or generally self destructive in some other way.
The answer is simple honesty! I've seen it before hundreds of times. Once you start to address the real undelying issues all the "other" symptoms will start to improve.
And incidentally, before anyone says "well it's ok for you, who had sympathetic parents" I know there are some people whose parents do react badly, but the evidence is pretty strong that even those who do so usually later apologise and come around to support us. Very rarely does it go so badly that the parent child relationship remains fractured forever.
So like Janet I would say absolutely "Time for honesty". I don't think you will get anywhere in sorting out your feelings until you can have that talk with mum. So do it soon!
Good luck.