Hello everyone, I'm currently in a difficult situation, it's affecting my mental health and I'm quite at a loss. 

A few years ago my mom started accusing my dad of cheating on her with other women, although she was caught years before cheating on him and unfortunately we have proof of that. (I'll come back to this part later). In the beginning I was skeptical of course, because I thought there must be some reason why she claims this, but until today I haven't seen a single piece of evidence that can confirm this and I'm starting to think that she's just being paranoid. Whatever my dad does, she controls him 24/7. Whenever he's on his phone or she hears the notification pop up, she accuses him of cheating. He has allowed her to use his phone quite a few times and told her to look for herself, but she still claims that he's cheating after looking into his phone. He even gave me permission to look into his phone, because I know more about smartphones than my parents do and I couldn't find anything that could again prove that he's cheating on her and I don't think he would do that if he was really cheating on her. Whenever he leaves the house to go to work, shopping or to the doctor, she claims that he's meeting other women, although apart from the things I mentioned, he rarely leaves the house, so there's no way he's seeing other women. Sometimes he asks her to accompany him so she can see that her accusations are not true, but she refuses to go with him, only to say again later that he's cheating on her. Again I don't think he would ask her to accompany him if he was really doing that.

It doesn't matter what you say or do, she becomes hostile towards you and is always suspicious about everything and everyone. She always likes to play the victim, blaming and insulting everyone, claiming that nobody loves her, that her children hate her, even though all this is not true. I'm afraid that one day she might do something crazy, because she has already indirectly hinted at committing suicide. I think this is partly just a scam to keep my father on a leash and get attention from everyone. The reason why I think that is because she cheated on my father a few years ago. She says she did it because she couldn't deal with her father's death and was at a low point in her life. I don't know anyone who cheats on someone while they're mourning the death of someone close to them, but what do I know? My dad wanted to get a divorced afterwards and she immediately wanted to take her own life. Of course her attempt was ridiculous because we found out that she wasn't in danger, it was just a scam to stop my dad from divorcing her. I know that suicide is something serious and it shouldn't be taken lightly. So it makes me really angry whenever I think about what she has done. I feel like she plays with everyone's feelings while claiming the world is against her. My dad has forgiven her and years later she suddenly started with the whole cheating thing. Again he offered her to think about a divorce, she refused, only to say months later that he didn't want to get divorced from her, so that he wouldn't look bad in front of his children. The reason why he wants a divorce is because she refuses to seek help and her behavior is affecting his mental health. It's not only affecting his mental health. My siblings and I feel mentally exhausted and living in this house is like living in hell. 

Honestly, I don't think we can do anything to change her mind unless she wants to seek professional help. I was looking for ways to help her, and then I came across an article about people with a paranoid personality disorder, and all the symptoms fit her. So I think that she might suffer from it and that she might also have some kind of attention problem, but I'm not a doctor, so these are just guesses. I wanted to know if there's anyone here who has been through something similar and how did you handle it.