I accidentally applied reverse voltage to arduino nano

Hi. I accidentally applied reverse voltage to arduino nano by plugging the positive and negative of my 7. 4 battery to the gnd and vin pin respectively. As soon as i plugged it smoke came fro arduino. I immediately turned of the power. I thought that the arduino was dead. However when i plugged the arduino through laptop it was working fine. :) when i again used my battery by connecting vin and gnd correctly, it worked normal. However when i checked the +5v port through multimeter, the arduino delivered around 6v through it. The3. 3v port gave 3.3v correctly. When i plugged it to laptop and checked the +5v,it gave correctly around 4.8to 4.9v. So what can i do now to get 5v from it even when I supply power through vin. Will my components (like Bluetooth, sd card reader, and various other which have +5v marked on vcc) get damaged if I use it even though it gives 6v? I also have 7805 voltage regulator. So will that be a good option?

Will my components (like Bluetooth, sd card reader, and various other which have +5v marked on vcc) get damaged if I use it even though it gives 6v?

Yes. The regulator is fried. It is very likely that the Arduino part of the board has also been damaged, so you can't trust it. Best to just throw that board away and use another.

Don't worry, we have all done that at least once.

try doing it with a $100 laser diode and not cry