Crazy MIL

So i definitely need to let this out.. my mil is freaking nuts. She is always texting my husband calling him names and telling him hes a piece of shit all because he wont give her money or pay her way. We have paid her way for 6 months about 2 years ago when i first moved. We paid all bills including her mortgage only to find out she gambled all her savings away because she was 'upset'. She told me not to tell my husband, but fuck that. I told him because i wasnt okay with her draining her acct on her gambling addiction and shopping trips while were busting our asses paying for her home and animals. Shes always having 'attacks' which involve her rolling around on the floor hyperventaliating and acting like a damn fool for attention. She has been transported to the er in many occasions and they say its all an act, theres nothing wrong with her and send her on her way. When we moved out she was so angry she threatened to cut my throat with a steak knife and bash my husbands skull in with a mag light. Two weeks before our wedding she told him i was a cunt and that i was cheating on him (which most certainly is NOT true) and that he should be marrying his ex, not me. Mind you, she came to my bridal shower an hour late, coked out of her mind and after an hr she just took off. Nor did she send her rsvp for our wedding. She came with her alcoholic boyfriend and sat in the fetal position rocking back n forth crying the whole time. She took off after that and she never came to the reception. My husband doesnt want anything to do with her because of her actions and her words. I dont know what to do anymore. All i want to do is tell that stupid bitch off but shes nuts and i dont trust what she would do. She was amazing when i first met her.. she was sweet and happy. She was the mother i never had. Then when she realized her son and i were serious she got nuts. Even her aunt and uncle said that she just wants attention and wants him to come back home to take care of her and pay her way so her money is all hers. Shes on disability and doesnt need to be. Shes just lazy and wants to complain that no one helps her. Id like to help her right off the edge of a cliff...

I try not to say mean things about her to my husband because no matter what, shes still his mom and i dont want to hurt him. But im losing my patience!!