Why am I like this

so I'm not the most social far from it and I feel like I can't connect with anybody my own age and I wanna but i haven't found out why is it just obvious that I'm a bad person? Is that why people don't like me? I have done some bad things before, mostly to my little sister and I regret it but I don't understand why I do these things and why people won't be nice and help me for once in my life. I think I don't appreciate people, especially my family enough, but I always just feel like a blank slate I'm not gonna do anything about it just waiting.

The million dollar question: Am I cooked?