Why does she give me the bad vibes?

Before I met her, my life was full of successes and promises. I did good in school and sports. I talked to alot of people, I was happy and everything was going good. But all of a sudden when I met her last year, life for me started to collapsed, I started doing bad in school and sports, bad luck rained over me for a year and everyone started to ignored me.

Why did this happened to me?

She isn't responsible for the change in your "luck" unless she intentionally did things to hurt you and sabotage your opportunities. There could be a many reasons why things changed. Did you get injured? Study less? Were you rude to people? It would be more useful to examine how you could be contributing to how things have changed.

Life has ups and downs, and much of it is beyond our control. That's why it's called "life", not "vacation."