It’s normal to have difficulties with students during a career as a teacher. Those who pretend to never have any discipline issue are probably liars. But there are teachers who are never overwhelmed because they are ready to act. Don’t underestimate the possibility of failure. Your lessons cannot be interesting all the time for all the students. And the students cannot pay attention all the time in all the subjects. Don’t feel ashamed because some students misbehave. Don’t be ashamed because you have tough times. Act!