ummm, not exactly? does it still work? if you spent more than 500$ on it i would suggest getting it checked out by a computer shop. you may have just broken one of the many internal parts such as the motherboard or powersupply. i once used a powersupply that was way to high for my computer when i was rebuilding it and i fryed my motherboard but it only cost about 125$ to replace that part then it was good as new...but lightening!? how in the workd did that happen?
Most likely, yes. You'll have to throw it away. But it depends on how much damage it has taken. If it doesn't work, it could be possible to parts for it to replace. But the problem is, it could cost more to fix it than how much the computer was worth.