I think I just remembered a childhood sexual assault

This morning when I woke up I got a flash of my mom's now deceased ex husband laying in a bed with me and telling me to touch his penis. Now I'm thinking I'm crazy! I can't stop crying and I have my kids to take care of today but I don't even want to get out of bed. What do I do with this information? I can't confront him. He's dead. If I tell my mom, it'll break her heart. My mom married him when she was pregnant with my sister who is 10 years older than me. He legally adopted my sister. By the time I was born they had been divorced for a year but separated longer. He move to a different state. Once my mom and dad went their separate ways, the ex would come in from out town to visit family and my mom. He'd stay at our place. Sorry for the back to back short sentences. I am trying to get my thoughts together and still function like nothing is wrong with me. How do I get to age 38 and remember something like this? I loved him like anyone would if they had a adult that "seemingly" was harmless that watched them grow up. Looking back some things make sense. My mom married him at 24, he was 25 years older than her. He met at her as a teenager when he was my GRANDFATHER'S boss! She said he would look at her as a teen but never said anything until she was an adult. Red Flag!!!!! And I remember him looking at me strange too as a teenager and would say weird things like "You've grown up to be a beautiful young lady" or "You're filling out nicely" referring to my body development. THERE WERE SIGNS! How did I not see it? How didn't my mom see it? I never felt completely comfortable alone with him and I didn't know why. What do I do?