Trial of Faith or something else?

My heart was broken when my boss told me that I was irresponsible about my job and as a result, two students left our class. I've given my very best to my work and try to avoid mistakes while proof reading my students' assignments. I believe that it's possible that I didn't notice some of the "mispelling" of the characters and I'm trying to be as careful as possible while checking my students' homework. Somehow, my boss has been keeping an eye on me all the time since the beginning of the new semester. Although I've known those students for over a year, the new school year is challenging for both my students and myself. They have more homework and things need memorized. Both of us are still trying to get used to this change. Yet, being called irresponsible made me really discouraged and sad about all the efforts I put.
Because of the conflicts between my boss and I, I need to push myself to go to work daily and it's getting more and more difficult now. I'm not sure whether I should hang on or move on and find a new job. I love those students with all my heart and pray for them every day, yet my boss told me that I have poor interaction with them, which isn't TRUE. On my way home, several hymns kept ringing in my mind. One of them says "Fear not, though the enemy deride and courage for the Lord is on our side. We will heed not what the wicked may said but the Lord alone we will obey (Let Us All Press On.)" Another says, "When dark clouds of trouble hang over us and threaten our peace to destroy. There is hope smiling brightly before us and we know that deliverance is nigh (We Thank Thee O God For a Prophet)." Those words brought me comfort and lightened my burden. However, I still need to find a way to cope with this challenge, either to endure this trial or look for a new job. Fortunately, it's a national holiday tomorrow, the Taiwanese Fourth of July, Double Tenth Day, and I'll have time to think about this matter seriously and seek divine help to make the decision.