Shader constantly maxed, especially when I enter combat; any help?

OK, so this isn't really a "new" thing for me. Truth is I got this rig about a year ago (i11700 with a 3060) and I've never been able to play the game smoothly on it. It's always been one type of lag or another, but the one thing I always noticed is that Shader bar goes max soon as I enter combat. It's been a hindrance for a while now, but now I'm at a point where I very well might quit the game, so I decided to drop by here instead.

No clue what is causing it... was hoping someone who managed to fix the issue on their own could help me out here, since I don't expect GGG to do anything for me at this point (they used to; they just no longer do).

Another thing to note would be that it is subtle and barely noticeable lag when I first launch the client, but after a loading screen or two, it becomes unplayable lag. Playing in groups is out of the question and trying something like 5-ways is just begging for a disconnect.

I've tried reinstalling, clearing caches, RAMDisk workarounds and everything in between... and nothing fixes it. If there is anything I can do to get this shit fixed, I will do it, so please let me know and I will do my best to submit w/e info is necessary.

Sincerely,
- Bunter