How do I stop acting like a baby?

At times, I usually don't take responsibility for some duties I'm assigned to (such as revising for exams; all I do is homework, but this is because, for some reason, I want a record clean of detentions). I also tend to moan and whine about things I want or don't have, and about how I feel I need encouraging to do stuff, such as trying to make myself the person I've envied. In fact, I can only do things if pressured to do them by someone else outside home.

I also get offended when I get called a baby or the r-word. I also usually end up with the few people who are as awkward as I am when everyone's free to mingle with each other; I just feel like they're a mirror image of me.