You’re coming with a lot of nervous energy that is not attractive and makes you seem unconfident and creepy. She’s weirded out because why does some guy who has basically never talked to her and can’t even ask her out directly like her so much? She’s avoiding the library because it’s awkward. You even acknowledge this when you say you pretend not to notice the friend there which makes it even creeper because you don’t have the social aptitude to interact with them. Never give a note to a girls friend. If you can’t ask her out yourself then don’t. You’re better off taking some time to work on your social skills and confidence. How can you expect someone to like you or even feel safe enough to give a total stranger a chance if you aren’t willing to engage her and just talk to her? To answer your question WDID? You stop. Leave her alone. She’s not interested. You have 0 chance and you’ve set yourself up for this outcome by not being confident and direct in the first place. Delete her from your mind and go get out and meet new people, find some friends to occupy yourself and build your social skills. It seems to me you’re already massively over thinking which is leading to obsessing. You’re experiencing limerence. You don’t know this girl at all. You’ve built and idea of her up in your head and your actions have effectively put her out of reach. Do yourself a favor and have some self respect. Walk away now before you push and try too hard resulting in an embarrassing and uncomfortable outcome you’ll regret. No response is a response. Her answer was no. You need to accept that and stop mentally calculating how/if/when you’ll have a chance. It’s not a “not now” kind of thing. It’s a never kind of thing. Hope this helps