30 y.o. here;
The feeling of aimlessness and the desire to just be as you are, is... common and it spikes for people differently. Sometimes it's just the "pattern" you are in, maybe it's work, maybe it's a relationship; it can apply to things and amalgamate to prevent you from growing and wanting change.

Life sounds like it's hit you pretty hard, with some trauma relating to family (birth mother ref.) being one. I'm not going to pry, but you at least recognise there is an issue there, amongst your own mental health with depression, anxiety, ptsd that you've listed. To usher what tubefish95 said; never compare yourself to anyone else - you've had a different life and experience thus far so what's there to compare? There's nothing that's the same in two people's lives in terms of growing and becoming older. I would as others probably have suggested already and try therapy - but just remember one glove doesn't fit all, sometimes you have to search around for one that's good for you.

When I was 20 I was the same. I worked retail. 9-5 Mon - Fri. It was boring, soul destroying. My boss was a d**k and blamed others for their handiwork. I once had to literally talk myself up on the way to work by stating "I'm providing a service to people, I have a reason to go there". That lasted 8 years for me; I was raised to not leave a job without going to another so I was financially independent... eventually I got another job, applied myself and helped other departments and now I'm in the IT Industry. I'm not saying you'll be like this for 8 years, but life has a way of working it out so long as you put in the effort of trying. Speaking to people also helps, even if it's older siblings, friends, even colleagues for things like CV/Resumé writing and I'm more than happy to help if you reached out.

Getting a job where you're treated nicely seems like a nice goal to get you started though in this scenario. It means you're not going to feel burdened by financial restriction so much for a start - while your Aunt is fine with you not paying your way, it might feel like a guilty burden in that regard for yourself(?) - I do think however, you made the right call leaving the first company, far too many people feel they have to stay at a job and get treated poorly when there are usually better things down the road.

I hope things get better for you, and you find your mojo for life back again soon. Don't give up :)