You use the word "supposed" a lot in your answer. Unfortunately, this isn't a scenario in which you make the right gestures and get an automatic result. If you're thinking about this in terms of what you're supposed to do, you're not going to get very far. There's no "supposed" here, only what you do and what happens. It's a system, and one that rewards what it sees as valuable. You can choose to be bitter, but better to learn about the system and how to get independence, recognition, and meaning from it.

A few years ago I was fired from a decent job as a paralegal. I'd left another place to join them and the reason I was let go had more to do with the fact that the person training me decided to stay rather than leave than my vision. But at the time, it was a massive blow to my ego and my vision of myself. I think unless you've been through it, and many people haven't, you can't really understand how traumatic being let go and being unemployed can be. It's humiliating. And so I get your frustration and the difficulty of your situation.

With that said, I'll say some things with hindsight that you may or may not find useful and you may or may not be able to internalize right now. The first is that you need to let go of your previous trauma with your last employer to the best of your ability. It sounds like you had a bad experience...I'm sorry that happened to you. But two years is a long time, figure out an internal narrative of what happened that you can live with and put it to bed in your mind. You're moving on and that's behind you.

Next I think you need to look at your situation from the outside, or from the perspective of someone who will hire you. Would you hire yourself? For what position? Why do you think you'd be good at that job? Why do you think you'd be better than the other people who would apply? If your honest answer to that question is that you wouldn't currently hire yourself, that's ok. That was the case for me. But you then need to say "What do I need to do to get to where I'd be seen as valuable in this position?"

Of the three things you said you did while you weren't working, only one, learning to use a cane, shows an interest in self-improvement and connecting with the wider world. That's bad. If you're spending your time noodling on the internet or consuming media, you're going to become less employable over time, not more employable. Support your partner by supporting yourself. Find something you care about, learn skills, read, and do exercise. Do volunteer, not so you get handed a job but to engage with people. The world isn't a machine where you push buttons and then have money and a house and stable relationships because you did some thing you guessed you were supposed to do. The world is filled with real people and real things happening and you need to treat it that way. Do things that are valuable for other people and you might get something back. It might not be fair, but that's the way it is.

Sincerely I wish you the best of luck.

I think this is all true, but the idea isn't to get hired by the volunteer organization. It's to get hired elsewhere, and the volunteering helps to make contacts and to improve your resume. If you're volunteering at an org in an attempt to get hired there, that's probably not the way to go.