I am so sorry that you Mom's have to go through this with your children, no matter how old they are. The only way for me to relate to that is that my Dad and brothers are alcoholics and addicts. I cannot imagine it being your child. I also have great sympathy for my own Mom because she is so stuck with them because how do you turn your back on your own child or husband? Somehow she manages to keep her sanity.
I am grateful today that at least I am able to turn my back on a BF, and allow myself to feel actual "hatred" (even if it's only for a few days) to get me over the emotional hump I need to get a BF out of my life. I guess this is exactly why I have never wanted to have children, and I have never committed to marriage, because I watched my mother very closely while I was growing up and KNEW I wanted no part of it. I feel so fortunate and I am so sorry that you are experiencing this.