PS is brush/heal/zoom/stamp LAG

I've been trying to edit some photos I took and my brushes keep lagging, whether it's the stamp, heal or regular paintbrush. It even lags when switching between tools and trying to zoom in and out. I have to wait for the screen to reset. I actually just had to just save and quit because the screen wouldn't refresh... anyone have any solutions?

My Specs.

THANK YOU! 🙂