Very similar thing happened to me when it came out that Roy Moore was a pedophile. My mom said that I shouldn’t just assume it’s true because someone accused him and then went on and on about so many men’s lives are being ruined by the Me Too movement and that no one waits all those years to talk about sexual assault or rape if it really happened...so I told her about my sexual assault in college and how even my best friend didn’t believe me so I never told anyone else including her. She was dead silent for like 3 minutes and then said that she was sorry that happened to me but that that wasn’t the norm AND that I should have reported it and not let him get away with it. Nothing like a little guilt on top of trauma. She’s never brought it up again and neither have I. I honestly think it’s about denial and not being able to deal with the fact that I was not only assaulted, but also that I chose not to report it or tell her.
I’m sorry you were raped and I’m sorry that your mom responded the way she did. There are too many people with stories like ours.