Decisions

I have been having a really difficult time lately. I can feel myself slipping back into needing a ton of pills/alcohol-- basically whatever I can get my hands on so when I'm not at work and my mind can be occupied, I have a way of drowning out any and all thoughts. I came up with an idea of how maybe I can help myself. I have read so many posts and most of the time the biggest help if you're in a situation like mine is to distance or separate yourself from what is triggering you. In my case, I live very close to my parents and I have to see them a lot per my mothers request. It's so hard to get through a visit that I often have to smoke (weed) or take a Xanax or an extra anxiety pill so I can be okay and not have a panic attack as soon as I walk through the door. My thought is to sit my mom down, or write her a letter and make her talk about what happened or make her acknowledge it. All I need is for her to understand why I can't be there and also why I will never have the relationship with my dad she so desperately tries to push on me. 

I need thoughts or some help. I'm thinking that if she still refuses to acknowledge what happened, I'll have no choice but to separate and estrange myself from both my mother and my father in order to fully heal on my own. This isn't something I want to do because my mom is my absolute best friend. Despite her lack of action when I needed her.... Has anyone been in a similar situation? Any helpful thoughts? I don't want to feel like I'm giving her an ultimatum however I can't continue to keep up this act just to keep her happy. I don't want to feel like I'm responsible for breaking up my family should she finally decide to do something, but I cannot heal if I cannot stay away from my father. I'm so conflicted. I don't know what to do. Im not the type of person that feels good about cutting my mother off. I just need her to understand.... This is all so hard. I want to heal so badly.