My mental heath during the covid-19 quarantine

The Covid-19 quarantine shut down has done a number of things to my mental health. It’s July 2020, so this shut down has been going on for +15.5 weeks, with no end in sight. The infectious virus has killed +130K people [in the USA], and cancelled all close proximity social gatherings for the next several months.
No movies, no malls, no shows, no concerts, no inside dining, no parties. Essentially the whole social calendar for everyone in the state [California]. And when  you strip away the social part of society, you get home-hobbies, with underlying anxiety and loneliness.
For about 8 weeks, everyone spent a lot of time at home, playing video games and doing video calls. I’ll admit that I enjoyed the first 4 weeks. Since I was already a homebody with a limited social circle, I was used to spending most of my time alone. But by the end of the 6th week, I was missing people like crazy.  With nothing to look forward to, it felt like I was trapped on a submarine.
I was adrift in loneliness.
But so was everyone else. Everyone I reached out to was doing approximately the same thing. Staying home, doing home stuff. All graduation ceremonies, and Memorial day festivities had been cancelled. Around this time, people started Protesting Police Brutality.  A dozen harmless people were murdered by police, which caused protests, which caused harsher police action. For a few days, there was a Police Enforced Curfew.
It was disorienting to think that we were all in the same boat, yet no one else seemed to be losing it like I was.
The panic was undeniable under the weight of hopelessness.    My hobbies stopped being fun.  I was scared of people. Every day for weeks I sulked around, not really knowing what to do with myself.
But Slowly, things started to reopen.
By week 12,  I was back to my pre-pandemic work schedule. Working Monday thru Friday in the office, with a dozen new social distancing rules, and still no social life.
Having a work routine helped alleviate the anxiety for a while, but then the sadness crept back in.
I’ve been back in the office full time for the past 3.5 weeks.
And this morning I rolled over for my alarm, and googled: how to be happy. Since I think I’ve forgotten how.
The search took me to a speaker, listing off ways to: make an impact, find a passion, and be thankful.  Claiming that doing these things would make you  feel happy: having gratitude, optimism, getting rid of bad habits/addictions, investing into social relationships, savoring the moment, meditation, and  setting personal goals.
My problem is that I need a task to feel useful, and a scale to measure my usefulness against, which is something that I used to get from other people.  Of course, I haven’t seen other people in several months,  so I haven’t really felt useful in several months. In fact, the quarantine eliminates the option to do many of the things that would contribute to feeling happiness.
But let’s give it a try anyways.
Quarantine mantra: I’m thankful that no one in my family has contracted the virus, or been assaulted by police, and I’m optimistic that eventually things will go back to normal.  I’ll be generous with all my friends, and enjoy the good weather today. And it is my goal to exercise and eat healthy food.