Oh, and she doesn't want to fuck you, so it's time to give it up already.
What you have here is not a crush or a fancy but something verging on obsession and by definition unhealthy. If you insist on trying to get somewhere with her, you should really leave out the part about thinking dirty thoughts about her since she was 18. That's pretty skeevy, pops. If I were her, I'd change the locks.
Ask her out, decently. Emphasize interest over obsession. Try not to sound like you have a secret room in the basement plastered with her photographs, and then take no for an answer. We can only hope that her rejection breaks the spell. She isn't the one holding you back, you know.