Heart beats faster n depressed. Plss.

I had brkup 4 months ago, bt the girl is infront of me in the class, evry tym i see her my all strength lowers down n depression prevails, my heart shivers n my whole confidence lowers down n others being her friend too ignores me too, i always thinks like its d end n the feeling of suicide came in me, my heart beats vry fastly nd i feels vry weak, i dnt hv any options left i think nd i cnt say this to my parents...this feeling of loneliness i cant handle, also i cant focus on my studies n keeps thinking abt her, i tried to make myself busy bt whenevr i get tym or doing my works or reading the thought revolves in my mind, may b this is the last tym i m writing, i hv mainly a sort of fear to her, i cant talk to her or anything plss help me anyone plss...