Accidentaly shorted Arduino Leonardo VIN pin to GROUND. Is my board fried for ever?
Yep sounds like it's fried. If you are new to electronics replacing the AtMega might be difficult as it is an SMD soldered part. You would also need to load the Arduino boot loader on a new chip and that is something that requires a programmer. 

I would suggest just getting a new Arduino and coming back to fix this one once you feel comfortable to troubleshoot the problem. That is a cheaper option compared to buying a programmer and parts you may need to fix this.