Having major family problems and really need some advice...please, i'm desperate :(?

I was abused as a little girl by my mother and somehow, I guess, by God's grace made it through... Anyways, My soon to be ex and myself have 3 kids. My daughter is now 21 and she has a child. Well, about a year and a half ago my husband ran out on me and my 2 boys then 9 and 13. We were married 21 years. Not all the time, but sometimes he was an abusive man, verbally and physically. It would be safe to say that he was mentally and verbally abusive more than he was physically, but he did have some good attributes... Let me just say, if this makes any since @ all- when he was good he was great, but when he was bad, it was more than a nightmare. I stayed that long, because i longed for him to change and I endured several abusive step dads as a little girl, so in my mind, I thought that no matter how bad their dad was, a stranger (step dad) would be worse. I know it sounds insane, but that's the way I seen it then, not to mention, I had no where else to go. I was a stay @ home wife and mom for the vast majority of 21 years. Well, we are now fighting it out in divorce court. My kids had to testify about the abuse... Here i am, this woman that does not know how to do anything but be a stay at home mom... Well, i had a nervous breakdown, recovered and am now going to school to be a nurse. The judge gave temporary orders for my soon to be ex to pay the house payment, all the bills and child support. He only pays me a 3rd of the child support and owes me about 12 thousand dollars to date. Well, my 15 year old ran away this morning. He didn't want to obey my rules. I grounded him, so he ran off. I reached out to his dad. I'd like to add that the boys have supervised visitation w/ him, because of the abuse. Anyway, I called his dad and he tells me that this is all my fault, because I made it to where he has no say in the boy's lives... Everything was my fault according to him. Words were exchanged. He then calls me back and says that he just wanted to let me know that he will no longer be paying the bills, or the house payment, that he doesn't want to live w/ his cousin anymore and that he's barely making it. He told me that I need to quit school and get a job, that my time for going to school has came and gone... Well, we have a court date on the 9th of Nov. He tells me that he's going to use the fact that my son ran off against me... My son came home and I THINK that situation is handled.. I don't know what to do. I'm a Christian woman, but am @ the end of my rope. It gets better. I have a daughter that is on drugs. She was 21 when her dad left. She did have a baby out of marriage, but she was making an honest effort to support the baby and herself and was doing a great job. After my husband left, well, her life went to hell in a hand basket. She has a 2 and a half year old, precious little daughter that loves staying w/ me and I love having her, but I have to study, cause I know that I have to make it through school. I HAVE TO DO THIS for me and my boys and that baby. Well, today, like several times before when my daughter comes to pick her up, my grand baby starts crying and clawing @ me, begging me, "Grammy, please don't let me go with cindy!" (she calls my daughter by her name instead of mom). She then looks @ my daughter's druggy boyfriend and says, "Josh is mean to me, he hurt my neck and slaps the bottom of my feet!" Well, this has happened a couple of times. I keep her as much as I can... I'm feeling really overwhelmed right now... My mother says that this is all my fault, because I stayed w/ the man and had all these kids... Maybe she's right... I'm worried that me and my boys are going to be sitting here w/ no water, or electricity, maybe even homeless if my ex follows through w/ his threats and then I've got this precious little baby girl that needs me so desperately. What am i gonna do?? Please, any words of advice, or anything @ all would be appreciated. Thanks so much and please excuse the misspelled words and poor punctuation.