Windows 10 Instability and data corruption issues

Since W10 (and I do like it) I have had multiple BSOD resulting in no longer being able to start windows, with start up repair saying
unable to fix errors, lots of file corruptions (system and “unable to open ...user/desktop/ as location is corrupt or unreadable), and on at
least three occassions (in 3 months) the start menu has stopped working (won't pop up) and some taskbar icons have dissappeared (usually at the same time as start menu error), mail and edge won't open, backup option becomes unavaliable, and windows update won't install up dates. Not all of the above at the same time but each issue has happen multiple times quite a short period.

When I have gone through all the usual steps to repair these errors, like chkdsk, sfc, create new user, reinstall windows apps and manually installing updates, stop/starting backup and shadow copy services, the issue has not been resolved and I have had to either reset my PC, reinstall windows or recover from a system image, many times.

Note with my most recent failures (the following occured all within one day), including start menu not popping up, mail and edge not opening, windows apps icons missing from taskbar, backup no working, and corrupt/unreadable /user/desktop location (which made me write this post/request for help), sfc verification was successful with no errors being found (confusing).

My gut feeling is its a memory issue, but I have tested my RAM with memtest (always passed every test) and checked out my SSD with
vender software (OCZ Guru) which reported 99% heath and tonnes of life left.

Is it likley to be any of the following?

1. not enabling overprovisioning within windows partition of SSD (but plenty of spare space);
2. the SSD is faulty; and/or,
3. malicious software (I have done secure erases of SSD but not HDDs).

Or any other ideas?

I am getting really frustrated, it is ruining my productivity, I just want to get back to a stable system and get on with my work.

I am considering buying a new hard disk, but don't want to spend £100+ if it won't solve the problem.

Any help/advice would be greatly appreciated.