I would love to leave and start again somewhere else, I'm sure I could do a much better job starting from scratch. I took up teaching because I wanted to do something worthwhile, but I'm beginning to hate this job.
The first thing you must do is to get your induction programme back on track. You should by now have been observed at least three times, have had three professional reviews, and your action plan should have been kept up to date. If there are gaps, speak initially to your school's professional tutor and negotiate an action plan to ensure that you receive the input to which you, as a newly qualified teacher, are entitled. Make sure that your new mentor is fully aware of the position. If you feel that the school's response is inadequate, let your named local education authority contact know.
It may take time to establish a working relationship with your new mentor so don't be too hasty about looking for a new job. But if things don't improve, remember that the deadline for resignations is May 31.
Sorting out "entrenched" bad behaviour in your classes isn't going to be easy, but neither will it be impossible. Without knowing what the specific problems are, it's hard to advise, but:
* seek the support of your mentor and colleagues. Poor behaviour is a whole-school problem and not something you can solve on your own. Ask for targeted observations to help you
* read Bill Rogers, Sue Cowley, and Chris Kyriacou, and apply what you learn carefully and consistently
* hard as it may be - problem classes can warp your view of the world - find a way to make a positive contribution, no matter how small, to your school. You'll find it easy to build on the status that that brings you.