I (17F) can’t stop thinking abt a girl even though I have a perfect bf (18M)

Im in a really happy 8 month long relationship with my sweet bf. Theres no big problems in our relationship, i am not falling out of love and hes never hurt me or betrayed me in any way. We love each other an insane amount.
I liked a girl for a few months before i met my bf, she was the first person i was crazy in love with, she was all i thought about and all i talked about. I think she liked me back, we talked a bit but we didnt get together which Im very happy about because now im with my amazing bf. I had a dream about her a couple days ago, in which me and her were in a relationship. It felt so real and I kept feeling like something was missing after I woke up. I caught myself looking for her in school a few times, it feels like I might start to like her again but I absolutely do not want to. I don’t know what to do and how to stop this feeling. I think I might only miss the version of her that was in my dream and not the real her. I don’t want to like her and I don’t want this to get worse or ruin my relationship with my bf. He’s my dream man, it feels like we’re meant to be, and we’re already planning our future together. I don’t want to like anyone else. What should I do?? Is anyone else in this situation?