UPDATE:
I started over using bulky yarn, an 9mm hook, and only did hdc and sc in BLO. I basically followed the pattern by Viv

R1 18 Fhdc, 5 Fsc
R2-25 top of hat 5 sc BLO, body of hat 18 hdc BLO

Top portion about 2” long
Total hat height is ~10” tall
Before joining 19” wide
Finished flat 10” wide

Used all of skein for hat plus about 20” of ww yarn to close.

WHAT I FROGGED:
Herringbone single crochet hat
Anxin_Crochet on YouTube
Adult size for me:
per video ch 43-44, H29-30cm, L55-56cm

This pattern looks nice but is SO boring. I feel like I’m not making progress at all, but it just takes longer to see it, I think. I noticed that I skipped the last stitch of the row about 10 rows back, so I have to frog it. :(