Photoshop CS6 Brush Issue

[Jombi]

I'm having some issues with Photoshop CS6. It was working fine the other day, and I opened it today and there were no panels or any type of workspace showing. That was fixed by simply resetting the essentials workspace. However, my brushes aren't working correctly. I wanted to show a friend a screenshot, but wanted to edit out some PC names and IPs prior to him seeing it. I chose a simple circular brush with a random blue color. I clicked and drug the brush across the image. Nothing happened. I tried every other sort of brush I have, same thing.

Just to make sure, I opened a new layer and had the same issue. Now here's the odd part, I closed all tabs and created a new tab with a 1920x1080 transparent BG. I successfully filled it with blue using the paint bucket. I took out my brush and wanted to draw red squiggly lines. Set my color to red and squiggled. It squiggled, but not how I wanted. Instead of leaving red lines, it erased the blue leaving a blue pane with transparent squiggles on it.

I can't find out why its doing this. Any help Neowin?