All of those sound like software issues. It could be antivirus, other drivers (not even GPU related), messed up Windows etc. Hardware by itself almost never behave like that.(...)
I'd reinstall windows if that happened to me and try on clean one with just GPU drivers installed, before you install any other software on it (aside games). Then check every time you put back software to see if it's not causing issues - that way you might find the culprit.