3f0 error + blue screen of death

[HelpMePlase]

Hi there! I've been having some problems with my laptop, a few months ago it was showing the 3f0 error and I followed online tutorials to fix it, and it worked until recently a microsoft edge automatic update messed with my laptop and caused many errors (which I eventually fixed using command functions and bios default settings), but during that time I had to reset and reinstall windows (and delete all my files at the same time as files were corrupted) and now the 3f0 hard disk error is back, but worse now.

I can boot up about half the time but if I try to really use the computer to download anything or open more than one program at a time (or even change volume and use a webpage) it shows the blue screen of death (stop code 0xc000021A) for half a second, reboots to show the 3f0 error, then I have to force shut down twice then it turns on normally. I have run the hard drive tests and they all show no issues every single time so I can't pin down what is wrong.

As I am an engineering student, I've had to download many different programs for my studies, which my laptop no longer allows me to do. I really want to fix this, and have looked into replacing parts of it myself (as it has been years since the warranty expired) but I don't want to destroy it more through these methods. I would appreciate any suggestions anyone might have, even if it's just to say that I should get a new computer, I just want to know if I can fix this myself as I am at a loss.