I'm really sorry unfortunately, it's very hard for a "sane" person to understand what a person with mental illness is going through, even if it's a close relative that knows the details of your situation. It doesn't help that there's a lot of ignorance about it..

It's not your fault. Probably it's not even your mother's fault. All you can do is keep trying and never lose hope and if your mother says another comment about your situation... take it for what is it - a comment from a person who doesn't really know the subject she's talking about.