Could you list off for us all the stuff you have been doing with your time? You never say what you are doing to help yourself. This makes it really hard for us to help give you suggestions.

Have you gone to a counsellor about this? It's really a very unhealthy fixation/obsession. We all go through unrequited love at some point, but you seem to be taking it to the extreme. A professional will be able to help you better than we can.

Like, you're taking this harder than I've taken break ups - I've always been the one dumped, and always by surprise. And I take them hard. A professional might be able to help you understand why you got so fixated on such a young girl, who never did anything to lead you on or showed signs of sexual interest, who you now feel even more fixated on with a broken heart.