Your gun is ruined. Send it to me along with $100. I will make sure it gets the treatment that it deserves. (Just kidding)
* Do not use rust removers or cleaners that contain ammonia, it will degrease the gun and that will make the problem worse.
* Do not use brake fluid or ATF as a gun oil. They contain chemicals designed to keep oil from attaching to the metal and will allow the gun to rust.
* If you use solvent that contains ammonia (Butch's Bore Shine, Shooter's Choice, Sweet's 7.62, etc), make sure you completely wipe down the gun after cleaning with gun grease or gun oil.
* Do not use rust removers that contain acid ("naval jelly", "rust neutralizers", "rust converters") as they will remove the bluing.
* Do not use metal polish (Flitz, chrome polish, Brasso, etc) to clean guns. They contain solvents and abrasives. They will degrease your gun and remove the finish.
* Use a light solvent or penetrating oil (CLP, Kroil, Hoppe's #9, etc) to penetrate the rust and stop the corrosion. Brush with a gun cleaning brush (bore brush, bronze parts brush). They are designed for use on guns, they don't scratch.
One of the problems that shooters typically encounter is sweat or alkali dust or soda pop splashes or whatever sitting on a gun for several hours during their range time and starting to rust the metal, and they spot it after the gun is cleaned and freak out. You may be doing everything right, just sweaty palms or contamination.