Sigh. Parents are overly attached. Need to vent. Advice is welcome.

My parents constantly have to know where I am ALL THE TIME. I'm a responsible working adult, who happens to be living with my parents. When I'm not at school, I'm at work. When I'm not at school or work, I'm at home. Last night, my class ended at 10pm, so ideally I would be back around 10:30. I was not back until 10:45 and they start calling me. I know it's because they are worried and they care about me, but it just pisses me off that they are waiting up for me. When I have to come back late, they complain that they didn't get enough sleep because they stayed up for me. I tell them--that's your fault, not mine. It pisses the hell out of me that it seems like they have nothing better to do than unnecessarily worry about me. It pisses me off that I still need to explain to them if I'm going to be 15 mins late. I know it's because they are worried but I can't help feeling this way. They call me an ungrateful child--that I should be thankful they care about me. They tell me I'm just a girl, that they fear the dangers of the outside world.. MEN, rape, pregnancy, car accidents, kidnappings. I know that. The world can be a scary place. But them staying up for me doesn't create some sort of magical force field to protect me. It does NOTHING.

I just want them to give me some space, some privacy, and treat me like an adult. I get so angry thinking about it. I think such mean and selfish things, like "Why are they so obsessed with me?" or "Why can't they get a life / find a hobby?" Then I remind myself that I am their life. I'm their child. But why does it have to feel so shitty?

I can't understand this. Maybe I'm just immature. Friends tell me, it gets better as you get older. But does it really?

-edit-

I'm at school doing homework in the library. 5:51pm, my mom calls me. "You should be coming back home right now. The library closes at 6 right." Yes mother...

Godamnit. I'm 22 fucking years old.