Help me i am mentally depressed

hello i am sandhya i am loving a guy from past one year i like him alot but now we are getting some disturbences in between us i become more possesive about him but he is avoiding me i am becomeing mad in his thougts i am feeling like dieing i am feeling wamit sensation alot daily due to this reason i am not feeling hungry i am not getting sleep even for a sec i am just thinking about him.i am really becoming a mad i cant stay any more like this i am really feeling to die what i have to do.i need him in my life what ever happen.why iam becoming mentally ill like this if he talks to me i am normal but if he dont ans for one day i am becoming a mad what i have to do what happening to me please help me.i may die with this mental torture.my brain and head gonna blow with his thougts please help me