First, my heart goes out to you. It’s great loss to lose inspired young teachers
Second, the fault is not yours nor that of your students.
Presently, half of new teachers will quit teaching by their fifth year. The problem is that we are not equipping teachers with the skills to scaffold students’ behavior. Your were basically taught crap about how to encourage and scaffold your 5th graders behavioral successes. Most universities provide “survey” courses about classroom management — never touching real evidence-base, practical strategies that teach self-control, group regulation, etc.
Only one university (Wright State University in Ohio) is presently equipping new teachers like you with practical tools with rigorously proven to resolve the issues you faced. My own work is based on multiple randomized longitudinal studies that test practical strategies that solve what you experienced. I sincerely wished you had been taught about how to use the PAX Good Behavior Game; your life and your students would have been incredibly different. You can read more at http://legacy.nreppadmin.net/ViewIntervention.aspx?id=351
It’s a tragedy that you were crushed by the poor preparation, and with tools not up to the task. My colleagues and I have conducted the first randomized control trial of pre-service training to test explicit strategies for your success and other teachers like you. Sadly, schools of education are happy to take your money, and leave teachers and students hanging.
Blessings on you and your future efforts.