My mom found out I was sexually assaulted

My mom went with me to my first doctors appointment for my first baby. The doctor then performed a manual evaluation on how far along I was because we didn’t know how far along I was. So I start shaking and I have no idea why and my mom said it was fine we thought I was just nervous. I put my feet on the foot stirrups and he warmed the tools then as soon as the doctor touched me I shut my eyes and all of it came back and I started crying silently then He put his hand on my belly to feel the baby and I jumped up screaming no and started shaking while sobbing. My mom looked horrified and just held me. I kept saying I was sorry and he said it was fine. When we got to the car My mom thought my current significant other was my assaulter. I said it wasn’t him and she asked who I said it was 3 people throughout high school. She didn’t ask anything else. Then she asked if my SO knew and I said yes but he “took care” of it and she said good.

The only thing is I lied to both of them it was 5 people not 3. The 4th was my cousin. He is my mom’s twin sisters son. He caused me so much pain and the 5th was my mom’s twin sisters father in law. He’s dead now and God forgive me but my tears at my funeral were not for him but for myself and for show. I was so happy he was dead. They all molested and traumatized me. Especially my own family members who I trusted. I couldn’t even look at myself until a year ago. No one knows, and my cousin is the favorite in my family. what should I do? Do I tell my mom? It was such a long time ago. Would she believe me?