Feelings I had for my classmate were obviously one-sided (pretty sure of it), so I made a reasonable decision to never confess to not make things awkward. In a few years since we graduated I finally moved on, although I never loved anyone this much since.
Yet all this time I had a desire to tell her about them. I would definitely want to know if someone loved me this much ever. Would she? I don't know. I don't even know if she is in a relationship right now or not.
I would really want to cite some scientific study that "Over 80% of girls have their self-confidence lifted after being told they were secretly admired (p<0.05)", but can't find one.
This person's advice is comprehensive and correct. You need to accept it. What you're feeling is not love. Love is something that is built up over years of being in a relationship. No relationship, no love. If what you're feeling is as strong as you claim, then the correct word would be infatuation, or possibly obsession.
You're going to come off as extremely creepy to her. Let it go.