Maybe the helmet wasn't XXL (as in mismarked or mislabeled). Get to a shop and try on NEW helmets from several companies, all XXL, to be certain of no fit.
And then shave your hair off and go Van Gogh on the ears.
The 12 Scariest Words in the English Language:
We are here from the Government and
we want to help you.
1968 Plymouth Road Runner, Hemi and much more
1968 Dodge Charger, 318 and not much else
1958 Dodge Pick Up, 383 and loud
1966 Dodge Van, Slant 6 and cool