I second what
@shureShote says above: there's an adjustment/adaptation period. If what we're talking about is aching sit bones, that eventually gets better. Fortunately, it also seems to be something you get past and it doesn't come back.
As for seats, most people either like flat (front to back, ala Fizik Arione) or hammock (ala Fizik Aliante). Shops used to have loaner fleets from Fizik that were odd colors (orange, yellow, purple) to hand out for people to try. Try calling some shops to track them down. You're most likely to find them at the sort of place with a $10k Pinarello on the wall.
If you decide to just buy something and try it, the old Selle San Marco Regale is a classic saddle for big guys:
https://sellesanmarco.it/en/negozio/approach-en-2/regal-leather-copia/ I'm not saying it's going to work for you, but it might be a decent first effort.
Also, how wide are your tires right now, and what pressure are you running? If you can fit them in your Domane, going with at least 28mm and running them at 70-80 psi will take a lot of the sting out of the road.