Is she trying to break us up or what is this?? *LONG POST*

I live with my fiancé, child, and his grandparents. Everything was okay but my fiancé and I are fantastic and a wonderful happy couple etc. In the beginning he was in a program at one point and his grandma and I talked all the time and when he had a pass him and I talked, she was really nice unless I didn’t fully agree...But my mother handled that because she made threats to me as a minor. My mother and my fiancé’s grandma HATE each other. But once I tuned 18 I moved in with them. Well just recently she’s been so Abusive! An when I’m abused I stay quite. My fiancé has been so upset with me lately because we constantly fight here’s why...

His grandma one night we were talking and all she had to talk about was all the girls my fiancé use to be with, how many of them claimed pregnancy, how many came to her front door claiming it etc. well way back between my fiancé and I our past use to kill each other. An she knew I was freshly over his when she said this. Well I didn’t say anything to him. Then a couple days later she began to just treat me like crap! Yelling at me for always doing wrong when he would be wrong in a disagreement not me she’d blame me for all his actions and everything she always protects him and that’s why our little disagreements turn into arguments, because she comes back in the room and puts her nosy ass nose in OUR SHIT! We usually kick her out but she comes right back in. Well everytime shes pissed at me for something little I just ignore her and let it be, but recently I was accused of claiming my fiancé raped and molested his sister all because They were sleeping in the same bed and she forced me to watch a video of the girl crying about being molested I told her no I don’t wanna see it, because I’ve been fr raped and molested but she insisted but I NEVER said anything honestly. But the incident of them in the bed just made me uncomfortable (she doesn’t live with us and I was in the room) well I mean look at my past. So anyways all hell broke lose she Always starts saying after any type of disagreement or argument oh I know your going to leave now so, when I won’t even say anything about leaving well that day I found myself walking down the Road alone and my fiancé and his sister chasing me well she came to pick “them up” knowing it’s 99 degrees outside and I have a 2 month old baby with nothing! She would’ve let us walk till we dropped. Well I went back home she’s coming all up In my face ect I wanted to leave planned too etc but In the end things calmed down I never said anything about my fiancé rapping or molesting his sister all I said was them in the same bed made me uncomfortable and she blew up on me . Well Monday was supposed to be better. Well my fiancé’s sister started telling me (she’s 7) that my fiancé only wants me because he smokes and he doesn’t love me anymore that he’s seeing someone else etc well I called my fiancé told him and he blew up called his grandma and she went after her for it but then at the end came back in the room and said the little girl said she wants me gone and that she wouldn’t have said it if it wasn’t for me saying my fiancé molested and raped her. I NEVER SAID THAT EVER. Then she yelled at me the whole car ride to my fiancé’s work that it’s always my fault for these things etc there better not be a fight tonight, I had enough I literally planned to leave my fiancé because my brain got over loaded ( god bless him) so I Ignored him for hours just to be safe till we got into it ( when I don’t tell him these things is because I don’t want to hurt him and his relationship with his family so I stay quite and say I’m fine but I came out about it today) anyways I couldn’t say anything cuz she was there well I told him the reason I wanted to leave and he went out got her she came back in there and said she wrote everything That little girl said down but it wasn’t what she told me she wrote “I as of my name am a viscous lair and lied about everything that was said about him and his sister, I am the cause for her behavior today and she hates me and wants me gone, she believes my fiancé loves me more then her” which when she’s over I just tend to the baby and try to let her spend time with him but she’s always with me and the baby so how am I stopping her??!!!!!! I told his grandma for now on I will leave while she’s there so they can bond and she blew up on me saying I’m childish and stupid for it that she’s 7. Really idgaf. Plus she lied on me cuz even my fiancé himself knows I’d never say he did a thing to anyone because I saw everything that night, anyways my fiancé freaked when he heard it and came after me after a while I said I’d go home since I Cause so much damage here and I’m breaking the family apart it’s my fault everyone is attacking her etc, and my fiancé and I broke up...I went to wash the dishes she says never gets done but they always are and gave her the baby but she was super busy then she said no it’s fine so I said okay and told her I was going on a walk to clear my mind and she informed me it was going to storm (which it didn’t) I cannot Bring my child or she’d call dcf so I said okay I won’t go, an went to grab MY CHILD and she started saying oh I can’t see my grand child before you leave your messed up I can’t believe you but I’ll be fighting you in court for this. then about 1 hour after that my fiancé came back in the room I was balling he layed me down and I told him everything, he was pissed he went and told her to never talk to me again I hope it works but now he understand why I’ve been acting this way and informed me I never did anything wrong it’s her and he’ll protect me from her nasty mouth! I hope today is better and he says he’ll always believe me no matter what and if she starts to abuse me again speak up right away. We made up said our sorry and realized in the end if she wasn’t around we’d never argue. But I asked him why she al of a sudden hates me so much and he says I don’t know he’ll find out. But I just don’t understand. She was so nice now she’s a nasty bitch! She’s old (57) so I hope the worst right now just because of what she did to me and him. I honestly don’t know what to think of this. What is this and what should I do about her??! We are great together (him and I) but I feel she’s trying to break us up. We possibly are having another baby and don’t know what to do about her because I don’t understand her.

She always says I’m raping him as well. when he clearly consents I’m 18 he’s 17.

Update

For those who don’t know sorry I forgot to say I am unable to move out I have no we’re to go. An I am talking with a case worker on getting a case plan for me to leave. But it’s going to take months. An all contact with her is cut.