But why the sun bleeds?
Nice shot, have you tried de-saturating just that color?
I would simply crop to remove that flare problem around the sun. Then lose a lot of the dark area on the right. Maybe end up with 4 x 5 ratio after straightening the horizon?
Well let's put it this way. My experience of life has been whenever a difficult problem occurs the first thing to do is to look for a simple work around.
You have a problem with flare from the sun and it will be tricky to cure. So this is my simple alternative suggestion.
There are a few other crop sizes which could be tried; for example going square and taking a bit more from the right side.