Thanks for the replies guys.
This thing has probably crashed approx. 5 times due to overheating, and I hope to god that's not the problem.
Tin, when you say that it's progressive, do you think that would apply to all cases? I ask because probably in the past 6 months or so I haven't accidentally crashed it due to an overheat, and it has seemed just as resistant to going down as when I originally bought it. Would you say this sudden decline is possibly due to progressive damage?