WOW. 50-60 kids in the classroom!! I wonder how you do it. Really. One of my 8-year-old classes is made up of 16 students and I have to really struggle to keep them on track and not have them walk about the classroom and hit each other... And I really felt good about myself for having achieved this atmosphere of cooperation after teaching them for 21 weeks. ........I'm sure I couldn't have done it with 60 students.
I teach in a state school and I have to teach certain very old books. Even though I feel that the books are no good I make sure that I do the lessons in the book as well. I teach the grammar, vocabulary however I think it is best, and then I use the lesson in the book as consolidation. Besides the fact that I am paid to teach the books that the ministry of education has given the kids I have found that students and their parents start complaining and consider that nothing has been done in the classroom if some progress in the book has not been made. So I make sure that the lessons in the book are done as well. I find that students enjoy it when, after they have learnt the grammar and vocabulary , they open their books and understand everything that is there in the lesson. Makes them feel confident when they open the book and the book is a piece of cake for them because they have already learnt everything that a specific lesson is supposed to teach them.
After teaching for 25 years I have reached the conclusion that in order to be effective we don't really have to be entertaining every single lesson. Kids also like to work hard and have the teacher appreciate their efforts.They also like the teacher to be in charge and lead them towards a specific goal. I started out
trying to please my students but I think I really started being a good teacher when I stopped worrying so much about them having a good time but started worrying more about the amount of language they would learn during my lessons. That doesn't mean that they don't play games, (boardgames, cards, slam, snakes and ladders, all subscribed to the teaching objective, of course) but not during each class. I usually do such activities when I have classes towards the end of the school day when kids find it more difficult to concentrate and do some teacher centered teaching (I really think it is necessary to model pronunciation) and writing and reading during the classes that are earlier during the day. I teach each class 3 hours a week . Kids
feel it when they make progress and appreciate the teacher's efforts. I think it is important for them to learn to use language the way a native speaker would use it. Learn how to introduce themselves, offer and accept things, invite people to do things together, talk about their family, lifestyle, possessions, holidays, free time, likes, dislikes etc. And I find that revision, time and again, of the language taught so far eventually leads to fluency and a feeling of accomplishment. It is also good, I think, to pinpoint at the end of lessons what they have learnt during the lesson. When they feel they have made some progress being bored or not bored is no longer such an issue.
I can understand how upsetting the experience you describe must have been. I have been in such a position myself and maybe more than once. You'll be fine. You'll find your voice.
Meanwhile, "happy teaching". I'm quoting Mark, the webmaster of
www.mes-english.com You might find some good teaching ideas on his site as well.