Jobs can be good- routine (sleep nights/work days), getting out of the house, social interaction, money, sense of accomplishment, contribution to society, having something to fill your thoughts other than worries, something to learn/mentally challenge you/get excited about, a feeling that you're working towards something to improve your life... full-time work helped me. Part-time jobs help get you into the rhythm of work and "baby steps" of the above while getting yourself healthy again-- I found part-time jobs helpful so I didn't feel like total crap when I took some "time off for myself." When I don't work, I end up staying up all night and sleeping all day and not accomplishing anything.
Could you afford to live with no income? Do you get welfare so you don't have to work at all-- and it's a matter of mental health and not money? Do you live free with friends/family/whatever and could afford to not work indefinitely? Do you think your days would be useful long-term with zero job and you could still accomplish something (mental health, hobbies, charity, whatever)?
When I haven't had a job and chose to temporarily live off the savings from all my full-time/side jobs, I wasted days for months. I had fun but accomplished very little. Eventually I just stayed up all night, slept every day, rarely left the house unless it was for some event, had nothing to show for those months and wasn't in much of a better mental place after 6 months of doing nothing/no work as I wouldn't been with "just" a month off of work.
If you get welfare, sometimes it "pays" not to work unfortunately.. If you get some sort of welfare or community clinic care or income-based benefits, see if working part-time would affect those benefits. Working 10-15 hours a week isn't enough money to live on for many people-- but it could meet some cap on welfare benefits, depending on what it pays. See if working part-time a few months would make you ineligible for any benefits you get/could get.
Normal business hour workdays kind of give a rhythm to life and a lot of people feel valued/meaning/new skills/learning from them, so I like to work as much as I can manage. Sometimes that's more than others.
The full-time work routine helped me, and not freaking out about money was a plus too. I felt more "normal" working full-time as long as I could. Part-time is nicer-- less work, more free time, more fun, still some worthwhile accomplishments to feel good about myself for.
If money isn't an issue and your life is paid from somewhere (welfare, family, spouse, savings, whatever), you could do volunteering or hobbies to try to get some regular daytime schedule and find some purpose/meaning/learning, instead of doing it through a job. Volunteering would mean flexible hours whenever you feel like it, assuming money is no object.
I wouldn't want to never work at all for years-- I've seen that turn into days of sleeping all day, drinking, video games, drival with people I know. Endless years of accomplishing nothing in my friends cases- they let never having to work make them never do anything. My friend complained about his monthly shower cleaning duties as if it was hiking Mount Everest-- that's all he's done this month other than play video games and waste time online day after day. He's done nothing in all these years to try to get healthy (mental or physical), not volunteered, not had meaningful relationships, rarely leaves the house, no friends/family hardly, no accomplishments, no learning/hobbies/contributions to societies- his days mean sleeping, drinking, legal drugs (in his country), and pointless non-sense for years. He hasn't made productive use of a decade of not working, and he still chooses to drink/do drugs (whichever is legal in his country), and pointless non-sense-- instead of trying to get himself to a stable mental place. But some people take advantage of 24/7 free time with those same welfare benefits he gets if they don't have to ever have a job to get stable, health, hobbies, volunteering, whatever and not throw their time away.
I'd "love" (in theory) not working and getting free housing/everything for life somehow-- welfare, the lottery, whatever, but mentally I don't think that would actually help me. I would never get anything done, my days blend together fast, I'd worry about money, the same mental thoughts would go through my head without work/projects to take my time, and I wouldn't be content or happy about that. Rhythm of normalcy helped me.
You could try the weekend job-- if you can't swing it, you have the option of quitting whenever. I'd suggest that, so long as that part-time weekend job income wouldn't mean you lose some welfare benefit if you receive any. If it means that, I'd say focus on getting stable then get a job you can live off later so you don't nix benefits you can receive before you're able to support yourself.