Hi,
I don't get why would you need 5A (Ampers) regulator ? I power FC, Camera, 600mW TX, OSD, GPS, etc... with 0.68A at most.
You probably meant 5V (volts) ?
Are you sure it's regulator that got damaged ? Cause regulator to me is the chip in SOT23-5 package, top right corner close to connector. But hard to tell from this picture without schematics.
Perhaps you could take a photo of your broken board ?