There are a ton of non-profits that appreciate help from anyone.

On another note, I was depressed and isolated a couple years ago after a breakup, living alone in a city on the other side of the country from my family and friends. Ultimately what got me out of my rut was regular exercise at the gym and reading Feeling Good by David Burns.

I can't recommend that book enough. Much of the philosophy behind it is rooted in Greek Stoicism, so if you just wanna cut to that maybe take a look at Marcus Aurelius or William Irvine's Guide to the Good Life.

What's important though is to not spend your energy trying to meet some invisible metric of "being useful", and instead be able to recognize the cognitive distortions that are causing you to be depressed.

That's why I suggested doing something like Rewilding. Nature doesn't care who you are. As long as there is a need for someone to introduce biodiversity and native plants in the area where you live, then probably no-one else is helping. So you can make the number of people in your neighbourhood caring about that go from zero to one.

Clean your living space.

Then find somewhere where people are littering, and get a picker and clean that up too. Take a before and after photo. You'll soon find out that you're not useless.

Eventually that will help give you the answer to:

>and why would they want me to help them and not somebody else?

If you're having trouble with the above, speaking to a professional therapist might help.