I saw your post the other day and didn't have anything constructive to add (my instinct was to say 'just see where it goes, but don't force it to be romantic', but I know so little about the situation that it's hollow advice), but I came across this article in the NY Times that might speak to your situation. It talks about limerence, which is a new word for me. I say might, because it might not be what you're feeling, but it's worth a read regardless, and the tips on how to overcome it in the article seem useful (and have backing by different researchers, so they're bound to have more material on the subject that would be potentially related to what you're going through).

Gift link so no paywall: https://www.nytimes.com/2024/01/27/style/limerence-addiction-love-crush.html?unlocked_article_code=1.RU0.qcHQ.OMOM2nOkSCqy&smid=url-share

All this advise is making me realize it wasn't just a crush.

I've not seen her for years, I try my best to have contempt for her, I don't look her up or make any sort of contact. She's dead as far as I know, and that's kinda how it feels. But I think about her often, I think about the regrets. It's been years of no contact and I'm still mourning losing this "crush"

Run. It will likely not end well

I find my crushes go away on their own after about a week. Your mileage may vary.

Think of all the aspects you like about her and think of all the ways they might be impractical. I know someone who said they had a crush on "the most delicate person I could have met" and I asked "but would delicacy be good for parenting" and then her crush ended.

Shit yourself in front of her. You may need to prepare with laxative beforehand.

Your feelings are yours, personally I'd just wallow in it and feel it and do absolutely nothing about it, you don't need to tell her, a crush is by definition sort of a fantasy thing. It's not her, it's some dream person you've attached to her. But I'm old so have been through this more times. It gets easier and then it gets fun.

The advice People give in the comments it's absolutely funny, it reeks of people who never leaves their house, or is women giving advice or some western Buddhist bullshit about letting go.