Aw man, IndecisiveMe, I can't give you any help ... just sympathy.
I haven't had any troubles since I put 15.2 on my PB360 (I received it with 15.1 on it, had w-a-y too many crashes to be happy and so downgraded to 14.2). It's been running like a champ since I installed 15.2 the first day it was released.
Maybe you could downgrade to 14.2 and then re-try the firmware update to 15.2?
Other than that, I've got nothing - just my wishes for a speedy fix.