That's a good idea - i often stop for a coffee or tea in the afternoon - maybe I'll try to skip that on my less-productive days.

If your teacher doesn't know how much you appreciate them, you should let them know. I work in schools and it's really nice when a family tells you that you've made a difference for them. Change can be hard, but that's how we grow. Next year you may meet someone else who will help you in the next phase of your life.