No, I did not overclock anything. Nothing running in backround, outside of Msi Afterburner and Steam. And I checked for old mod files, so it was a clean installation. SSD had free 100gb space after install. It might be a hardware problem, but I have played Fallout 4 on even weaker rig(4gb ram, 1gb Vram), not going over 35fps, but it was stable, so I think my current rig should be fine, considering it worked perfectly before.