Hello, this buzzing is called "Coil whine" and it is pretty common, it can be either from the GPU or the PSU so make sure you know which one of these is causing the coil whine sound, there are many methods posted online that will help you to identify which component is whining.
On the other hand many tech experts, the majority I guess, will tell you that coil whine is normal and harmless and no it doesn't necessarily mean your PSU is dying or it is going to harm of fry your desktop. I was in the same boat as you I had the Corsair CX600 PSU since 2013 and back in 2016 it started to produce some coil whine, I kept using it for almost 2 years without any issues, I wanted to upgrade to a better PSU but all I could find in the local market are cheap PSUs and most of them are bronze rated, I checked this list:
https://linustechtips.com/main/topic/631048-psu-tier-list-updated/
None of the mentioned Tier 1 PSU were available in the Lebanese market, eventually I bought an EVGA G3 750W Gold from Amazon Canada and shipped it to a cousin's address there and he brought it to me ...
Good luck finding a decent PSU here but while searching for new one don't take a brand for granted, like "Corsair are good and they wont coil whine", do your researches on the exact models you will find and pick one that isn't known for coil whine. There is a nice site that does some good reviews on almost all power supplies:
http://www.jonnyguru.com/