First, it sounds like your crank arm was butchered prior to not being able to get the pedal to release. I'm pretty sure your knee/ankle would give out long before you'd pull a properly tightened pedal out of a crank arm.
Second, the easiest fix is a thread insert to fix the stripped threads in the arm.
Or you could just replace the whole crankset, which might be cheaper than buying just a drive side arm. There are lots of cheap cranksets out there.