Sorry you got caught on the crossfire of these two people whose diseases have taken over their lives long ago.
My prayer for you is you get to a face-to-face Alanon meeting, find a sponsor and work the steps. There's nothing inherently wrong with you at all. When you can find tools and a relationship with a Higher Power you will know just how much you are worth.
I also suggest lots of Alanon phone meetings at this time. Like, all day if you need to.
Take good care of you and those babies rather than focusing on the alcoholics which will get you nowhere.