The meanest mother-in-law

I needed a place to vent. Soo here I go! My husband and I are high school sweet hearts and have been together for over 10 years. We got married July 30th 2016. I married my best friend and we are soo happy together. At the age of 19 in 2010 I made the foolish mistake and was cheating on him with a guy online. Lesson learned! He made the choice to forgive me. Now here comes the nasty part... His mother.... She is the devil himself. 4 years ago she had foot surgery on her right foot and was given oxycotin and lidocaine patches for the pain. Well 4 years today she's still on these pain killers but was given a cancer patient level ones and she complains they're not working..... nothing works for her pain.... diluated, morphine, fentinal do absolutely nothing. She is now to the point where if she doesn't get her level of pain killers right she is the nastiest, most hateful person. Shes attacked me mentally and emotionally by talking to her son over the phone. It started in 2014 when we got engaged, it started off with me being slut and a bitch. Then 8 years after my cheating incident she uses that as her ultimate weapon. It went DOWN December 7th 1017 when we moved into a new home. We were watching t.v. peacefully downstairs when I receive a massage from her on Facebook saying I need to take her off. I didn't know she tagged me in something. That turned into a phone call to her son screaming "That fucking devious little bitch who needs mommies and daddies money and that I'll cheat on on him again." She even attacked me about my pcos and the struggle of having a baby. I heard her laugh under her breath about me having kids. It got bad!!! Her son tried to calm her thinking she had been drinking but she swore she's was sober... it got to the point we're she was telling her own son to shut the fuck up. I could hear her as clear as day across the room word for word...... while she's screaming at him she's sending me the nastiest texts. So I took her off Facebook and that made things even worse but I've just had it, I'm about to be 28 and she's almost 50. I NEVER spoke back to her once I only said I don't want to fight. I saw my husband's phone and the text between them disturbs me. It's like she's done nothing wrong but throws me under the bus cause she knows she can. Then an hour later she calls crying to her son and texts me come down tomorrow with him to take her to the doctor and that she is sorry. I have forgiven her 6 times over these years........ I know she stalks my page cause if I post something she Instantly complains to her son about it even though it's not even about her, so I blocked her completely. The last message I saw her send was when we're both on his phone and she says your my son and I raised you, tell that little bitch to be grateful I had you. Im worn out and need advice. I haven't talked to her since December when she attacked me. I was never raised to disrespect anyone! soory rant over.... im just done.