It's gonna be difficult to hold that thing down to bend it back. Preheat it in a roaring campfire then fish it out and beat on it, maybe re-heating with a propane roofing torch or weedburner. Maybe you can get it in the vise & continue heating with a propane weedburner.
3/8 steel isn't hard to bend when red hot but you have a compound curve there. When its back straight, you could add bracing. But it might be designed as a soft point, to save your tractor mounts. That flat plate sure wasn't intended to take the load it got. Go easy next time.
Replacing the flat plate as said above is a reasonable suggestion too if you have the eqpt to cut a new one. It's mild steel, it wasn't and can't be heat treated.