Ok, hear me out, I think I managed to fix my flatline problem (I mean it should be, I managed to play for one hour without a crash and did multiple side quests), which was usually this error:
Error reason: Unhandled exception
Expression: EXCEPTION_ACCESS_VIOLATION (0xC0000005)
Message: The thread attempted to read inaccessible data at 0xFFFFFFFFFFFFFFFF.
File: <Unknown>(0)
Issue in my case was with BIOS. I have Aorus Elite b450 MoBo and this is literally last thing I wanted to do because it's not really recommended to tamper with BIOS however last crash I had in Overwatch also revealed to me it's a same error of crash, which made me realize maybe it's not game's issue after all. What i did was I went to update BIOS to latest version, however on the site for Aorus MoBo, when you go to download bios update, there's big notification in red letter that if I'm about to update my BIOS I should run EC FW Update Tool beforehand ''to avoid 4DIMM DDR incompatibility on 3rd Gen AMD Ryzen™ CPU. '' Reason why I didn't suspect a lot in this case is because PC came sort of configured and I just placed my SSD into it without more thinking. What happened in a long run is, that it locked 0.1 of my RAM away from Windows and if Windows cannot acces that RAM, its only obvious games would be locked away from it. Now my Windows show full RAM capacity, and game as of now seem if anything, more stable.
So steps to what I did (For Aorus B450 Elite):
1. Run EC FW Update Tool
2. Downloaded latest BIOS update from their site (in my case it's F60e)
3. Unpack zip file, and placed B450AE.60e file on USB drive (It has to be FAT32)
4. Restart the PC, then go to BIOS UI and then to Q-FLASH
5. Find your file and update it, restart computer and let it run a bit uninterrupted.
Now these are steps I did in case for my MoBo, if you have any other MoBo, be sure to read a good portion about it before going to the BIOS updating, and be careful.
In my case, I'm willing to apologize because in the end it was issue from my end. I hope rest of you folks can fix your problems too.
TLDR; Check out your PC properties and if your config is not showing full RAM capacity (like round number as it should), it might be that issue.