I usually have trouble with helmets as well. I cannot fit into any Sandbox helmets or most Bern helmets, even if they say XL or XXL.
Smith Holt XL did fit for me, however. That is my first recommendation since it's EPS approved.
I also found a Bern Macon XXXL. I think it's a discontinued size or at least I had a lot of trouble finding one. It fit perfectly, but this is a hard hat and not EPS certified.
My main issue with helmets is that my skull is pretty wide, so most helmets pinch the sides of my head to the point that they hurt. That's my reason of going for XL+ helmets. Hopefully my info helps you out abit.