I'm assuming it is more of an idealistic interest in her rather than sexual? If so, I don't think its unusual (at least to a certain degree). It comes up in literature a bunch. Pic-related's writings are probably the best example of this and are incredibility spiritual. I myself do this for a celebrity who is alive, despite not knowing much about her and having a relatively normal love life. It's more of an idealistic thought-loop than genuine romantic interest. My advice is to use the feelings as a wellspring for your music/writings, and don't let it control your life. Read some Dante, read about courtly love poetry.
