Edwing Hull Corrosion ssue

[MallardRain20]

I have a 1999 Edwing 21'. It has been mainly used in salt water its entire life but never moored. I notice today some pitting on the bottom of the hull so I decided to jack it up so I could take another look. I notice were it sits on the trailer in my opinion there is a decent amount of pitting probably due trapping moisture. The pictures I attached are one of the more severe spots from what I can see. I'm kind of at a cross roads on what to due next so any advice would be helpful. Some questions I have are.... How do you fix it? Is it ok to use in its current state? Does this look severe ?

Thanks
Andrew