What exactly do you think is wrong with my Arduino? Did the software get corrupted?
Yeah, the little Atmega8/16u2 that is used for your USB2TTL communications. Unfortunately, that circuit could use a little more protection from Electrostatic discharges and the occasional introduction of greater than 6 volts.
So, what usually happens is the fuse settings or the flash gets tweeked and it stops working. 999 times out of 1000 you can just reflash the "DFU"/Atmega8/16u2 with firmware located in the hardware folder and you are back in business. But, you need an ISP programmer (Arduino as ISP works too).