Trouble with my field

Dear i have trouble with this lesson, honest when i was in class i got my brain refuse for any kind of part these task. it feels like i don't want to face that day, the day when there taxation class.. it's sound too much but it happen to me. I spent so much energy to do that lessons but i got nothing, i'm not competent... my eyes my ears cannot connect to my brain even I've stayed all day in class. Simply, i didn't like my field...