Apparently my GUID was leaked and used to hack. Any advice? Or is it literally just buy the game again on a different account because that seems to be the general consensus.

Currently there is no indication that GUID's can be spoofed or duplicated. The only way a GUID can be compromised is by physical access to the account via Origin.  

Please do not create more threads about the ban unless EB admits that the detection is false or it turns out GUID's can indeed be spoofed.