Omg, that is a big story. I'm not such a persone who gives great advices, but i think i know a
littlebit how you feel.
I can't say a lot of things you can do, because you've tryed it all already. First i'm glad that you have Shannen and you're dog's to help you forget you're problems. Second (and i know you've tld it her) but i think you're mom doesn't know how she is not only ruingin her life badly, but you'res to...I mean, why does she wants children, if she can't care of them on a normal way!
I'll hope you're doing well and we on this board support you for more than 10000.....000000 % (even shannen!)and you know that!
We're always there for you (behind the computer)!
Much love and Take Care
Charlotte