My Mom And Meth.. Need Advice

This is going to be really long but i really need advice. I'll try to make it as short as possible. My mom is about 34 years old now and apparently started using meth when she was 15. My grandma told me times before when she had me or my two younger siblings that she was able to quit, but its not quitting if she's back on it. I remember when i was in 6th grade not wanting to live with my mom. Until the other night i thought it was my fault when really it was the meth. She got locks on her doors, slept at weird times, never let us in her room, throwing up occasionally, being really mean to us, she yelled a lot. Thats what i remember, she yelled a lot and she was always in her room. So since then I've lived with my dad and i still do today. My sister (13) and my brother (7) now live with my grandma, my moms mom. Their relationship is not that good at all. They argue every time they're around each other. I go over to my grandmas on tues. and wed. for her days off and my mom sometimes comes over or we pick her up because her license is suspended. I see a counselor but i don't really get advice. And thats what i need and want. To me, my moms drug use is like a cycle. And its caused by her childhood. Her mom was always gone and her dad was never there for her emotionally, he was bitter she says and he still is today. The cycle starts with my mom coming over and my grandma being negative and saying "Whats that on your arm?" and my papa says (in front of me and my little siblings) "Thats where she shoots up her drugs." Thats NOT okay for my little brother and sister. (continuing about my "Cycle" theory) And so she comes to my grandmas and everyone is horrible to her so she goes to her house or wherever and does drugs to make herself feel good again. Me, i already know everything I'm already exposed. I just don't know what to do in a situation like that. So what do i do? I try to tell my mom why the kids won't talk to her and why things are like this and that if anything is going to be okay again her and my grandma have to be okay first. Because thats almost the root of the problem. But whenever i try to explain to her things like that it turns into an argument and she hangs up. Its really stressful for me and I'm only almost 16. My dad is a complete a****** to me. If i was upset and crying in my room it would make all the difference if my mom were there to just lay down with me or bring me water. Just be there for me, you know? I need her and i love her and care about her. Its s***ty to see your mom go down such a deep hole and to see the house you used to call home turn into complete s***. Looking back at it now it was always a struggle. Now its a struggle. My grandma has to save her house, support the kids, take care of her sick brother, all while my mom is stressing her out about money and rides to places. My grandma loves her and wants her to get back to normal. Only thing is, we don't have money for rehab. She's been in detox, try-county, jail, everything. We just don't know what to do and her absence is killing me but i can't have a relationship with her while she balances drug addiction. If anyone has any solutions or advice please help me out. Also thank you so much for reading this if you have. alexisc12@hotmail.com