A little hard to read, But while your PSU is more than enough power, I think that where you should start your trouble shooting.
But it sounds like you may be drawing too much power from your electrical outlet. certain parts of your home can only supply so much power before it trips the switch for that area. I am not an electrical technician so i can't tell you how to check. but a way to test this theory is by Disconnecting all other unnecessary devices while you are using your computer. TVs,fans other computer's etc. and see if this happens again.
I had a friend run in to this issue when i brought over my PC to his place. when i started to use mine both of ours became unstable. He knows a little about house wiring so he got me an extension from a different corner of his house and everything was fine. he did some work after i left and we didn't have this issue afterwards.
Unless you have the knowledge on how to fix this or the money. just try this for a while and see if your problem comes back. if it does I would try testing your PSU somehow.
There is information on how to test PSUs with a multimeter (i believe) look in to it.
I space a lot since I am dyslexic, and i don't know if you mentioned that your PC is still working or not. If its not fried and still working consider my input