I only had two pairs of over-the-ears that I liked. One had
  side-to-side adjustability rather than the C-clamp "one size
  fits all" crap that even some of the expensive headphones have.

  Another good pair had the C clamp but it was a looser clamp -
  probably wrong for smaller heads but perfect for mine.

  The rest I tried through the years? Pain within an hour. I had a
  similar problem with glasses. I need wider glasses. Nobody told
  me this through the years, and they'd just give me whatever I
  asked, and I'd always have these grooves in the side of my head
  Expensive glasses that didn't fit. I didn't know they didn't
  fit. I just thought I had to suffer.

  Then Zenni Optical many years ago put me through the fitting
  process and that's when I found out that I had a wider head. WHY
  the optometrists through the years didn't try to fit me
  properly, I don't want to think about (because of how expensive
  they were... compared to Zenni) but I'm just glad to know now.