Minecraft using 50+% of CPU, cursor randomly freezes

While trying to test Minecraft 1.12 I noticed in task manager that minecraft was using 1.6GB of the 2GB of RAM I assigned to it. Not only that but my CPU activity was over 50% while just rnning Minecraft and Task Manager.

Not only that but I was getting serious spikes in framerate, it would go; 120, 144, 33, 250, 300, 144 (I don't remeber the exact numbers of coarse). Along with framereate spikes came random moments where my mouse would just stop working for a few seconds. It would happen in Inentories, Pause Screen, regular Gameplay, and outside of Minecraft (desktop/Task Manager)

[NOTE: restarting the game again helped with the cursor issue... Still thought I should report it]