Why doesn't my mom shut up

I had friends cancel beforehand for personal reasons and I'm rarely ever mad about that but my mom always makes me think that they stood me up or something she always gives me this fake anxiety and with specifically these 2 friends. They don't treat me bad but she acts as if they do by telling me beforehand I really don't get it. I'm not mad at my friends at all but she just keeps on giving me a reason to feel sad or annoyed even when I wasn't before. She always say something nasty like they stood you up or they are fake friends. But she always does it in a way were she acts like she's in denial and if I defend them she'll just start shouting and telling me that she can't say anything and then I'll get in trouble, I'm so sick of my mom