Am I normal? Is it normal that I always want to be alone under my type of circumstances?

[Ariana]

I never want to hang out in public places with my family. I don't even like to be around them when I'm home. I share a room with my sister and I always basically throw her out of our room because I just want to be alone. I don't know why I have closed myself off to them life this. I guess because I usually get into many arguements with my mom especially and it's just my way of avoiding it by getting some peice and quiet. But I also noticed that on days when I am ESPECIALLY not feeling confident in my appearence, I don't even want to leave the house. Or I don't go to certain places that I think would have more people there that are my age. I have not been doing this as frequently as I used to. But I still do it. I am usually a very funny, open, fun person especially when it comes to hanging out with my friends. But even sometimes I avoid going anywhere with people and I tend to make up excuses just so I can stay home and think. I do this more with friends who are more distant rather than with my best friend. It is not because I don't like my more distant friends. I don't know why I do it.