I got bored from things too quickly?

I had a problem which I don't think is a big one but it's really troubling me and that is that I hate my life.

1. My parents are too strict... And I am trying a hell lot harder to be good at study, sports and every other field.

2. Once upon a time I was a great chess player best in my region then after some months I lost intrest in it and now I lose even from smaller ones.

In studies almost in every year , I am topper in my class for some few months but then once I lose my intrest which eventually happens after some months my grades went way too poor from 90-60 aprox. %

The same happens with every thing I do whther its sports or anything

please note that I am also not socially connected guy I always prefer to stay alone 24 hrs a day though I have many Friends they always call me but I always prefer to stay alone .... it's like I like to stay to alone...

thanks, Prince