So, for a while now I've been experiencing this dealbreaking issue when attempting to mod minecraft in which, at several times, panning the camera causes a violent lag and stuttering view turn that either moves too slow or to fast, making it hard to even walk properly in a single direction, and that's because I've only been troubleshooting in creative mode. It's almost like the camera pans in locked angles, like 15° at a time, and causes major fps fluctuation (VSync turned off, no screen tearing, just the chunky camera specifically). Seems to be exclusive to modded Minecraft, though vanilla has also been underperforming.
Now, my computer isn't really the best, mainly due to a mediocre GPU and a CPU that doesn't seem to do it's work properly, as well as RAM leaking, but I never had this issue in my first 3 years using it. It's 64 bit Dell Inspiron 5557 laptop with a Core i7-6500U 2.50 Mhz dual core CPU, 16GB of RAM, Nvidia Geforce 930M 4GB GPU and Intel HD Graphics 520 integrated card. I've also updated to the latest version of 64 bit Java 8 (build 211), were using a bunch of performance mods and had only 32 mods being loaded. I've loaded larger modpacks before, and even with with enormous lag, I've never experienced this camera stutter on this computer before. In fact, it happens regardless of what mods I use, the moment it stops being vanilla I begin to notice this stutter and it only gets worse as the map loads.
Anyway, I have no idea what other information to put here right now, I am kinda lost. I've been googling for weeks and only found very isolated complaints similar to mine, some had random solutions that I've already attempted, others fell into oblivion. Would anyone have any idea of what is going on?