Plese help..its serious..?

help me plese...i like a girl very much..i told her about my emotions about 1 n half yesrs ago..she is in my college and same cl..she said that she was not interested in me...but before that we were really good friends..i use to help her in every situation of her need...we used to talk..but the day when i told her about my emotions she stopped talking with me...i really couldn't accept the fact that she has rejected me..she used to to stare at me...nor could i get over her...even if she rejected me.i was pushing to get close to her..i used to message her about the college work schedule details whenever i got to know about it....i was rather being too clingy to her...i was so much engrossed in her that i really wasn't able to forget her...she was constantly on my mind..i just used think of her..did no studies and nothing..i was just pushing and pushing myself to get close to her because i thought she might think of me after sometime..but she never talked with me