I was in a similar situation in my first year, and a bit in the second year as well- without too many details, a guy considered me his really close friend because I was one of the few people that didn't tell him to **** off in the first week. I couldn't bring myself to tell him that I couldn't stand the sight of him and it got worse and worse- he was constantly calling, knocking on my door, etc. In the end I visited the Chaplain, who I knew he got along well with, and asked him to have a word. Maybe it was a wussy thing to do, but I knew that by getting the Chaplain involved, this guy had someone to talk to if he needed it. Is there someone similar that you could talk to? A welfare service or chaplain perhaps? You can't live your life for this girl.