Basically I want to say from my head teacher, but his occupation is not really that; should it still be capitalized?
No, don't capitalize. Even if it was his occupation, it's not really correct. Here's an informal but comprehensive list of capitalization rules which I regard as sensible. See especially rule 3:
Capitalize a person's title when it precedes the name. Do not capitalize when the title is acting as a description following the name.
Ms. Petrov, the chairperson of the company, will address us at noon.