Share your experience!
Hello @DonovanF and welcome to the community!
Most probably that was an app acting app, maybe stuck in the background consuming a huge amount of resources.
As your phone is working fine now, you may just forget about it and continue using it normally. But if you want to be sure this may not happen in the near future, I'd suggest that your backup using Xperia Companion (all important data except settings and apps) then perform a software repair using Xperia Companion. This will do a clean installation of the latest firmware and will also wipe your internal memory. Follow the steps given in the blue link, do not connect your phone until prompted to press volume down while plugging USB cable.