Random issues with speed and mouse??

I can't figure this out for the life of me.

The other day I used my macbook and it was fine. Today I upload photos from my latest photoshoot and it doesn't want to work properly. Not only is it slow as mud when I try to drag photos from iPhoto into Lightroom, (it simply does NOT do it. I have to force quit eventually. So frustrating.) but the mouse/pointer isn't working as it should be. When I hover over options and things it does not highlight them, it does not acknowledge hyperlinks, etc. It still lets me click wherever I want but it's just not normal behavior. It does it with my wireless mouse and trackpad, neither makes a difference.

I've tried restarting a few things, system updates, software updates, letting it sit for a few hours and then trying again, etc...

I've tried doing some Googling but I don't even know where to begin in pin-pointing what is going on!?

Please help 😟 I can't edit this way.