Stuck pedal, I've tried everything
I think your pedal is a lost cause.  Even if you did get it off in the current condition, reinstalling and later removal will make later-you hate current-you.
I would disassemble the pedal from the outside - remove the axle cap, locknut, cone, and bearings, then slide the pedal cage outboard.  You may have a second set of bearings inboard, or a bushing.  The bearings are probably separate, but might be caged.  These are all &quot;spare parts&quot; now.
Now you should have a bare metal shaft poking out the side of your bike crankarm.  It will be hardened metal, and probably chromed and oily.   I would use a grinder or a file to create two flat(ish) spots on either side of the widest part of your axle.  Don't need to be perfect, need to provide a place for grip.
Then I would use either a pair of stilsons (aka a pipe wrench or monkey wrench) or I'd put the bike horizontally with that axle pointing down into a secured bench vise.  At that point you should be able to use excessive leverage to back out the axle.
Think three times about which way you need to turn the axle.  It should be left-hand thread but that flips if you're working from the back-side.  Its easy to be tightening when you want to be loosening.

Once its out, examine both the internal and external threads.  Identify why it was so wedged, and whether there is damage inside the crank.  If you have a 9/16&quot; 20tpi left hand tap then chasing the thread gently would be a good idea.  If the thread is munched, then consider options.
Finally, go shopping for new pedals.  Whether you want to stay with flats or go to clipless/cleats etc.
When you do install replacement pedals, use something as an assembly lubricant.  Grease at a minimum and is better than nothing.