I've gotten in way over my head and I don't know what to do anymore. Advice?

I had a pretty terrible childhood with my mother. She was the only parent I had (aside from an abusive step-father who 'stepped in' after my dad passed away). I was molested as a child for many years and she did her best to cover it up and make me out to be a liar so that my brother wouldn't go to prison for it. My mom became a meth addict at an early stage of my life and continued drug use, as well as selling/manufacturing methamphetamines throughout my teenage years. When I did 'the right thing' by informing my school principal (whom I trusted) about her drug problem, she convinced him it wasn't true despite having drug paraphernalia and as soon as she got back home, she came to me and threatened that if I ever did anything like that again, my 'brothers would hunt me down and make me pay'. I had four brothers, I was the middle child. By the time I was 18, I wanted her out of my life for good. When I worked a job (since 16) she made me pay all of the bills or they wouldn't get paid. I could never afford to leave, I was stuck.

Then, 18 months into a long-term relationship I became pregnant with my first child and frantically worried about what I was going to do with the baby. I was 19-years-old and I considered all the options. In the end decided that this baby would be my chance to start a better life. When I was 4 months along in pregnancy, the father left me and basically disappeared from my life. She suddenly decided that she would be a responsible parent to me. She stopped using meth in her life. She promised that she would be there for me like she had never been. We started to become friends... I thought our relationship had finally started to mend and would be okay. When my son was born, I came straight home from the hospital to my grandmother's home (instead of my mom's) because my brothers were still using drugs.

It's been 16 years since then and I've had three more children. I've been married and divorced. I've recently been diagnosed with Complex Post-Traumatic Stress Disorder. It had never even occurred to me that my anxiety and stress and fears were an abnormal thing, much less symptoms of a disorder. I thought this was a normal way to feel about life. I'm terrified of everything and I've been this way almost my entire life. The only conclusion to be made about this is that my childhood played a HUGE role in me having C-PTSD and I had never been treated. I can no longer work in a work environment, at least for now (still holding out hope!)

A year and a half ago, I took my mother in to live with me. She's 65-years-old and retired. She has scoliosis, type-2 diabetes, extreme bladder weakness, bipolar disorder, morbid obesity, heart issues and I believe she is gaining symptoms of early Alzheimer's. Over the years, I've made my opinion very clear about my brothers. They still have drug/alcohol/legal problems, constantly. If it's not one thing, it's another. I have repeatedly asked her to not bring them around my children. The drama and problems are entirely too much to bear for me, let alone my children.

I currently live on a very tight budget, and we agreed when she moved in that we would split the bills in half. That makes our total household bills. She continuously invites them over to my house, feeds them MY food (which I've asked them and her to NOT do), and she gives them money like it's going out of style. The past two months, she hasn't even paid half of her portion of the bills and we're in danger of losing our electricity/water/garbage. See, my youngest brother is 32 and homeless. Child services took his children from both parents because neither were fit to care for them. His ex kicked him out of their apartment, since she had a job and he didn't. He hasn't worked in years, doesn't even try to. So she gave him her minivan (since she can't drive anymore) despite the fact that he has a suspended license and gets pulled over in it repeatedly. He lives in the minivan. She pays for the gas and insurance to keep the vehicle legal. I don't know what other money she gives him or any of my other brothers.

The more I've tried to keep him out of my home, the more she rebels. She has everyone convinced that I'm just a selfish b**ch and heartless because I refuse to help him because he refuses to help himself. She wanted me to invite in all his drama into my home and let him stay with us. I was homeless too not long ago. I fought hard to regain a home for my children and myself. No one did it for me. My mom refused to even help me a little bit. She continues to go behind my back and let him in here when she thinks I can't see/hear him. She lies to me and my kids about them and the situation. I'm tired of all of this unnecessary stress. My KIDS are sick of it. I feel the need to protect them and I'm afraid to even try. I'm afraid of her/them. I don't know what to do. I feel like the right thing is to remove them from my life... but how? I feel like my C-PTSD situation isn't boding well anymore.