Welcome to Using English.
Your teacher was wrong to say "never." Your sentence is correct (or it would be if you had capitalized "I"). So is "She's loving her new job" or "You are being a jerk" or "He is hearing a lot of people say what a good job you are doing."
You can use it when it's strongly related to a situation in the present, and either new or likely to change.
Student or Learner