I am in my 7th year teaching. Keep it up, you're doing fine. I think I read in a few places that there is about a 7 year learning curve to the job, where finally, you feel comfortable with things. I believe this is true. Here are a few things to focus on:
-Classroom management
-Being prepared
If you can do those two things, you are going to be in great shape. One of the best things you can do for yourself is to obverve other teachers. Ask if it's ok to sit in their classes. See what they do to manage the kids, you'll learn a lot! Every teacher should do this as they all should be constantly learning.
It is ok to threaten with worksheets sometimes. Use whatever you find effective. For me this year, I have told my challenging (behavior) class on a couple occasions that it is a choose your own adventure day (remember those books!?). If they behave, we will go through the material, and I'll try to give a little class time to do the homework. The other choice, if they don't behave, is that I'll have to assume that they already know the material, and they'll get a quiz in class instead. The choice is theirs. It has worked well for me.
Typically you have to have a whole bag of small tricks to get the work out of them on those tough days. The more time you spend teaching, the more tricks you'll develop. Good luck!
The only bad thing you can do is to give up. NO MATTER HOW BAD THE KIDS ACT, THEY DO WANT TO LEARN. Don't ever think otherwise.
Chris