Dear (put teacher's name here)
As of now, this year has been pretty sucky. Life just hasn’t been too sweet to me, you know? But having met you, I think my life has gotten just a bit better. You might not believe it to be a lot, but trust me, it is. I have never enjoyed school, but thanks to you, I look forward to learning. You make education fun, and that's a surprise coming from me. Its true when I say this year hasn’t been the best. But even if you didn’t intend to, thank you for putting in the time and effort into caring about your students, including myself.
Yours truly (insert name)