Dream About Sexual Assault In Shower

I have this lucid nightmare where I am standing in the shower naked. I am a 12 year old boy in this nightmare. The shower was one of the places I was sexually assaulted as a child. Suddenly I hear a door open and then I hear pants fall down. Then this figure gets behind me. It's the man who molested me as a child. Except he has no face and his penis is extremely long depending down to his ankles. To me the penis is the source of all my suffering. He grabs my penis and starts to aggressively fonder the glans of my penis. I push away telling him to stop except he doesn't listen and his penis becomes hard and erect. Then I orgasm, except when I do all I see is solitary penis shooting off semen. I don't feel pleasure I feel distress. Then I see me in the shower again. He doesn't let me go and he tries to penetrate me with his penis. I tearfully beg him to stop. But he doesn't starts to rape me. At this point I wake up.