I had a rough time being isolated for several months on end, especially near the end where I was possibly a hair away from a legitimate nervous breakdown. Even though things have been largely "back to normal" for me since mid-late April, I feel like the effects are still lingering and that I get anxious/depressed more easily than I did before.
I feel you man. Though in my case it existed pre pandemic and weirdly the pandemic didn't make it worse but I was also self medicating with benzos so that's a whole other can of worms. But ya the moment you realize you haven't felt actual happiness or pleasure in close to a decade really breaks you down. Even when you achieve big accomplishments or my usually shitty sports teams do well or even when I got fucking married I feel the rememberance of what used to be joy but it feels so hollow and empty and fades so damn quick. The way the pandemic has fucked with me though is despite already despising people as a general rule due to their shittyness it's forced me to actually see and deal with it so I couldn't make up some copium about "I just hate people because I'm depressed". Now it's blatantly clear that I hate people because people are complete shit.