How do I move on?

I realised I've been in love with a friend for like five years or something that I don't even see anymore. It took me at least two of those to stop being in denial about my feelings, and by which point she was out of my life. As much as it kinda feels nice to imagine the life we could have had together, and I dream about her a lot, I think moving on would be the healthiest thing for me since I'm moving away from my hometown soon and having that 'what if' constantly in my brain is straight up unhelpful. People normally say time heals or whatever, but that's really not my experience, I think maybe because I never got closure or straight up said goodbye to her. She's unfollowed me on all my social medias so I guess she doesn't want anything to do with me, yet that's not even enough to prompt me to just turn the page.
I've never expressed my feelings to her, but she once asked me out like years and years ago and I rejected her, which obviously caused a lot of friction in our relationship because I did like her back, I just didn't realise it at the time.