All Photoshop brushes missing after recent app update

So I logged in PS a few days ago and all the brushes were gone. Not just the custom brushes I'd downloaded, but all of the default ones too; including kyle's dry media and wet media brushes, and the splatter brushes that came with the last few versions of PS CC. And since there's no more "reset brushes" tool in the drop down settings menu, I can't figure out how to get them back. Weirdly the brush history bar displayed the last few brushes I'd used when I'd last been in the app (all of which were brushes that mysteriously disappeared), but they weren't in the brush panel. Anyone else experience this?