Layers Bugged Out? Or the Eraser?

[#1]

This issue has been going on for a while now. When I go to erase something, my eraser either doesn't erase anything or erases one little pixel. I reset my eraser tool, but it still did the same thing. I uninstalled and reinstalled Photoshop, but it was still acting up. Lastly, I created a new document and opened a backup to my drawing, and it was working fine at first, but it started doing the same thing AGAIN! I went over to my layers and turned on layers on and off again, but the layers were glitched. Turning off one layer would still show that it was on, but turning on and off again would finally show it was off. Recently, I've seen it glitch so bad, that when I move a picture, it shows a duplicate instead until I zoom in. Same thing happens when I try to erase something on the drawing I mentioned earlier and it doesn't show any different at first until I zoom out, where it shows the erase I just did. I'm just so lost...

[#2]

This issue has been going on for a while now. When I go to erase something, my eraser either doesn't erase anything or erases one little pixel. I reset my eraser tool, but it still did the same thing. I uninstalled and reinstalled Photoshop, but it was still acting up. Lastly, I created a new document and opened a backup to my drawing, and it was working fine at first, but it started doing the same thing AGAIN! I went over to my layers and turned on layers on and off again, but the layers were glitched. Turning off one layer would still show that it was on, but turning on and off again would finally show it was off. Recently, I've seen it glitch so bad, that when I move a picture, it shows a duplicate instead until I zoom in. Same thing happens when I try to erase something on the drawing I mentioned earlier and it doesn't show any different at first until I zoom out, where it shows the erase I just did. I'm just so lost...

[#3]

It could be the video card. Check if you have the current driver. Also try turning on/off Use Graphics Processor in Preferences > Performance.