Wonderings...

I've been feeling very discouraged at my job lately. I've been having trouble putting into words why this may be, so I thought I'd try to write it out.
I know that I like kids. It's why I wanted to be a teacher. I've talked with my assistant principal and she asked me, "Why did you get into teaching?"
"Because I love kids." I respond.
"Then just love them." She replies.
It sounds so easy.
 Being a teacher is way more than just loving my students, which I do.
I get discouraged because a lot of my students have bad attitudes and bad manners and lack social grace.
Now, to be fair, I said a lot...I know that a lot of my kids are good. I'm just finding it harder and harder to focus on them. And, I also know as a teacher that I'm supposed to teach them these things that they lack. AND, I  know that they are only 13...But, in the course of a class period or a day, how is this possible?
 I also feel resentful to some of the parents. As a parent, I am teaching my children these basic social skills, so why aren't they? Yes, I know that they are probably trying. Yes, I know that a lot of them worry about where their next meal is coming from. Yes, they are probably thinking too, in the course of a day, how is this possible. But, it makes my job hard when I have to teach 40 or so kids that they should say excuse me when they bump into someone.
I also have issues with the educational system in general. I know I can't control that. That doesn't make it any easier to deal with. Something is not right in our system and things need to change.
So, my question to myself is, can I continue to be a teacher? If I leave my urban school district for a suburban one, will it be any better? Should I even be teaching? There are other ways for me to work with kids without feeling so much stress....right? I know I will figure out the right answer for myself and my family, I just hope it happens before I end up in the crazy house in a straight jacket....