Awe Crap, did I fry it? Oh btw, Hello!

So I should start by saying hello.

I bought a Mega 2560 and was instantly hooked! I've been playing with it for a few weeks now and decided to build a balancing robot.

I received a H bridge motor driver last night and finally got a chance to try it out tonight. My recycled ATX PC power supply that I usually use is under modifications, so I decided to use the 12vdc SLC battery that I plan to power the robot with to test the H driver board out with and connected it to the Vin and GND pins.

Long story short...

I decided to use the 5vdc provided by the mega for a pot and a switch and accidentally connected it to the same rail on my breadboard that the 12vdc from the SLA was connected to... damnit...

It was probably only connected for a few seconds before I saw light dim and realized what I did and yanked the wires. Now the tx/rx lights are always on and the Atmel chip gets HOT fast if I even plug it in to USB... Am I screwed? Is this going to be a seriously expensive hobby if I keep doing this late night while having a few drinks!? HELP!

Thanks,
Steve

That board is screwed. Probably best to get a board you can replace parts on for your next one.
Some options other than '328P here:
http://www.crossroadsfencing.com/BobuinoRev17/

Just look on ebay for some cheap clones and use them ... as long as the board does not say made in Italy you're good... use an uno untilyou get the hang of it ..