My Mother the Heroin and Crack Cocaine addict.

Hello, I'm a teenager that has just joined the COAP, I'm new to all of this and I don't really know what I'm doing, all I know is I need serious help because I'm on the verge of breaking. i think I'll start from my birth, I was born and I lived with my mum for 5 years and on my 5th birthday my mum gave me to my nana to stay with, at the time I thought it was just one of them times when I just go and stay at nanas house for a few nights and mummy would be back for me soon, but that didn't go to plan, I'm 14 now and it's almost 10 years I've lived with my nana. since then my mum has been in and out my life. When I was younger everybody used to tell me my mum was just poorly and she will be back soon, then she came back pregnant when I was 6  and stayed with us at nanas house. When my brother was born it was one of the best feelings of my life, but 2weeks later he got taken to care. I didn't know why but I soon learnt that my brother was born a heroin addict, that my mum had been taking heroin while she was pregnant with my brother and when he was born he was ill,that's why the people took him away. That broke my mums heart and determined her to go and get her methadone from the chemist every day and go and visit my brother every day, she wanted to prove that she was good enough to get my brother back and she fought for him And got him back when he was 6monthhs old. Mum stayed clean for about 5 months after that then she was soon gone again. I have the closest relationship with my mum and I'm the one who never gives up on her even when the whole family do. she continued to come in and out of mine and my brothers lives, everytime she came back she made me believe that this time she was gong to stay and become clean so we could live with each other again, and each time she would get a phonecall from someone 4-5 days later offering her drugs, and she'd be out of that door like a shot, leaving me heartbroken and depressed for weeks. Eventually I would get over it, and just as I would start gettin used to life without her she would come back and leave again. She's still doing it to this very day, but this time was different. She came to stay and I truly really believed it was time to get my mum clean and she was really going to try, but as usual she left again and left me heartbroken, then called me two days later telling me she's sorry. Now usually I would tell her it's okay and I forgive her , but this time I told her I hate her and I wish she was never my mum, i told her I'm not forgiving her and she can do it on her own. this scared her because she knows if she doesn't have me she doesn't have anyone, she keeps phoning me asking for chances and I keep saying no, telling her to leave me alone, but as im putting on a hard face for her , inside I'm dying, I'm petriified for her future, I'm scared she might get really upset and overdose thinking I don't love her, when really she's the one person I love more than anything and anyone else on this planet. I'm just scared of her dying, two of her bestest friends have died from overdose and im scared she's next, all I want her to do is to get better and be my mum again, I have to be hard with her otherwise she'll keep on taking the mick, but I'm scared to be too hard incase I cause her to overdose or kill herself or something,,I'm just really really scared and I need some help on how to manage my feelings please, thank you for reading and I'm sorry it's so long