I'm a 22 year old guy and live with my parents and sister. My problem is that I don't talk to them even though they've never hurt me (not to my knowledge) to deserve this treatment. Whenever they ask me something, I reply with one word at most. Even if my day has been great, as soon as they try to communicate with me, I (in 95% of the cases) get very distant and almost don't reply. Plus, I go to school and work so they only see me on the weekends.

I have no problem talking to my best friend or my colleagues, even though I'm not the chattiest person in the world. When it comes to my family, however, I suddenly feel some kind of a block as if I didn't want to get close to them. They feel like I don't care about them, which I of course do. It's as if I was afraid of getting close to them. I still have no idea why. I don't think it could have something to do with my childhood, since it was alright and they have always loved me.

I don't understand my behavior and I know I'm hurting them. They all are getting pretty mad because of this but how am I supposed to tell them why I'm being so withdrawn if I don't know? Is there any way to find out why?