My father just finished a grief counseling class and he said one thing he learned was that every family had problems and it was usually the kids. Of course, he said it tongue-in-cheek but I'm not sure he wasn't right. Family can sure knock the wind out of you and I've decided that I just need to carry on and not worry about what the other guy is doing/thinking/saying. Take care of you and hopefully things will straighten out. Also, know that you aren't alone in your struggles.
Sounds like you have had a real period of trials. Sometimes it just seems the rain just keeps coming, but oh my, how we love the "sunshine" when it returns to our lives. May God send his blessings to all of you.