I am seeking forgiveness to Allah for making erotic fantasy story

Assalamu alaikum. I am very ashamed to share my story but I am scared. A few months ago, I used an Ai app that generates 18+ stories. So I used this app for fun. I used command some prompt and that app generated some incest story. One story was like, (my cousin disguised as my mom and doing erotic things with a boy) Naujubillah! But at that time, I read that story and made me aroused and ejaculate few times. But I realized what have I done. Now I am feeling very scared that I made a big sin, I think I made same sin as adultery. I am regretting now. I don't know why I was supposed to used this app, I forgotten principles of islam. I crossed my limit. I usually do Salah, Will Allah forgive me if I repent?