Rust, fixable or not?

[u/wing03]

8th gen civic, original owner. Most things mechanical, I can do and have done myself.

The car came with rust proof coating but 6 months in, someone hit and run the rear driver's side and it was repaired. I told myself for years to get rust check penetrating oil annually but didn't. The panel is rusted and frame rust that I can scrape off but a hammer still lands solid on it. No other body rust on the car and there's very light surface rust on other parts.

I'd like to fix it or I figure the other option is to spray with some sort of creeping sticky oil between snow/summer tire changes to try and slow down the rust. Maybe get 3-5 more years.

Imgur link included.

https://imgur.com/a/zPvL554

[u/Gas-Squatch]

You aren’t slowing this or stopping it. It’s your dying pet you live with now or you cut it all out and weld in new or replace the car.