Here's something from a kid... Being a kid can SUCK. Really suck. Especially when you are on the brink of being an almost-adult but the parents don't seem to realize it. Almost-adult responsibilities, but being talked to like you are a child. ("Because I said so," etc.)
I second what Sourland said. Define YOUR definition of responsibility, and ask them what else you will have to do in order to meet THEIR definition. Like I said, it sucks sometimes, but the parents DO call the shots.
I'm not saying you do this, (although come on... We ALL do this sometimes) but doing your chores probably doesn't count if mom and dad are always having to get on your back about it.
Remember that in addition to sucking, being a kid can be pretty cool, too. I had the flu this last week, and because I wasn't off and college or in an apartment by myself, I had people to take care of me. We don't have to file the taxes. We don't have to worry about the utility bills. We don't have to think too much about saving for retirement yet.
So just hang in there... We won't be kids forever.