A few ideas that come to mind:
- Have you checked for unusual logs? [HowTo] Find error logs
- How hot does your CPU at work? I see it’s at 50°C after 5min of usage, which isn’t unusual per se, though you may want to check if it goes too up, and dust your computer if so.
- A last suspect would be the power supply, from an instable electric grid to a faulty or weary PSU or plug.