Cheating, uninvested apathetic students.

Today we took the second test. Try as I might I could not get the class to be quiet. I took off points, diciplined them and nobody would listen. There was a constant hum.
This afternoon I graded their tests and I could tell some of them were cheating. Two wrong identical answers from kids sitting right next to each other. People with correct answers but no work and wrong answers on prerequisite material. People with answers that were almost right but completely missed the point. For example, 50x instead of x=50 with no explanation of how they got there.

I'm annoyed. My kids aren't invested in their educations. If they are just going to cheat why should I take the time to grades tests? Why should I teach them anything? I might as well just give them the answers. I'm not invested in those kids anymore. I loved them, really wanted to work for them and now I'm annoyed.

I shoudl clarify a bit, this is second period that I'm talking about. First period did awesome and averaged 85 percent on their tests. They are the ones working hard and learning a lot.
I should have ripped up some tests today when kids wouldn't stop talking, me telling them I was going to take points off was not drastic enough.
Part of the problem is that kids finish early have to sit around and wait and get bored and start talking. Plus someone always has their hands raised so I can never have a second to monitor. GRRRR>>>>>>I'm bitter.
I want to tell those kids I'm not getting paid, I don't have to help them, I'm here because I care and if they are going to cheat I don't see the point any more.