How can i help myself?

My mum knows I suffer from mild depression, yet its a taboo subject for her. I find it hard to believe most times that I do. I have a supportive friend who has been through the same thing, and says I can talk to her anytime, and she's made me realise that I need help. So when I cry in front of my mum, telling her I feel tearful for no reason, she tells me (and has done so every time I feel low) that I'm wallowing in self pity. She has said this so many times. She said there is no reason why I should feel tearful. She told me truthfully that I should so things to occupy my mind and I'm the only one who can help myself. I agree with that totally. But she told me as long as I 'keep this up' I might kill myself at 25, and 'what a waste that would be'. She said she'd been through the same thing before, which I know of, and I could try many, many counsellors, but in the end its all up to me. She said they never work for her. For the past month, I have hit rock bottom. I constantly need my friends around me, because I'm terrified to be left alone with my thoughts. There are some days when the feeling is just not there. And there are other days when its worse than ever. Right now, I feel totally helpless, but also guilty that I feel this way, and totally stupid. My mum continually telling me its self-pity makes me feel awful, and worthless, which results me in self-harming. I somehow need a confidence boost.