The only sure cure for seasickness is getting back on flat water, and better, on land.
I’d look at houseboats and cruising on the inland waters as a viable “escape pod” option in much of the American SE.
Thanks for the advice. I've actually considered a small live aboard cruiser with the ability to do over 20 knots. Six foot seas once, in a 20' power boat for over an hour, didn't bother me at all. It's when the boat is stopped, or moving slowly, that seems to trigger sea sickness in me, but only in salt water. I can handle any boat motion as long as it is fresh water. Running in from offshore, nausea symptoms disappear as soon as we enter the river channel.
I believe if I can ever get past it, and that may take several days at sea on a small boat, I think it might be the answer to being at least semi-cured.