The truth is, after 5 weeks, if consistent procedures were not established in the first weeks of school, it is going to be a challenging year in that class. However - all is not lost, but you will have to have more patience than you would like to have. Make sure in all dealings to remain calm - you are the adult and do not let them take any control away from you. That is not to say, you can't go home and vent, etc. The best thing that was shared with me 30 years ago, is to keep their instrument to their face if you have a class that is talkative.
If they are talkative, you as the teacher - talk less (pretty important anyway) and keep them playing. You may have to let some things go, however if they are playing they are not talking. Also, I found that the better the procedures we establish the better our classes are.
Something that is sometimes overlooked - creating a relationship (positive teacher - student) with each and every student is important and it takes time. Students behave when they like their teacher.
I hope what I have shared is a little helpful to you. You will get better - it just takes time. I wish you the very best.