Iwillfearnoevil,
a very religious sounding "name" maybe there is something you believe in & maybe you know that if you work at it & help yourself you will find help.
What you posted about your mum could so apply to me that I almost cried for my own daughter(16) as I know that how you feel is how she feels & what she fears. But there is a difference between you & your mum - several in fact.
1) you are you not her.
2) you have so much more access to information & help than she or I had when your age - so you have a better chance of finding out what's wrong & getting the right (repeat right) help.
3) you can learn by her mistakes - & your father's (like you can choose not to become an alcoholic because you don't like what it's done to him & to you through him.
4) yes, you have some of your mum in you but you have some of all your ancestors so ok, you too may suffer depression but that doesn't mean you'll automatically become her.
Take hotasfricks advice too. Pm me if you want to chat.