Questioning living after toxic relationship

I'm 29f, have a history of childhood abuse and neglect. I lost both my biological parents at ages 10 and 12, raised from then by my alcoholic step-dad. I'm trans and I was recently diagnosed as neurodivergent and CPTSD. I don't know if I want to continue living much longer, though I'm trying to look for reasons to keep going.

My ex-partner, let's call them Mia, recently cut me off after four years. Mia was the most important person I'd ever met. I have the most memories of joy and laughter with them out of anyone and we had planned marriage and a life together. But Mia is also neurodivergent and CPTSD and our relationship grew very unhealthy in the end due to stress on us both. Mia finally snapped and accused me of "classic abuse" and then wrote a text saying we needed to separate, saying maybe in the future we could reconnect after long term healing and acknowledging both of our parts.

I thought we would separate quietly at this point, so I agreed to separate and to take accountability for my part, but then Mia went on Instagram liking reels about abusers and horrible men every day for weeks (and sending them to their sister who also liked them publicly) and went on Reddit saying I was a covert abuser. I found this Reddit and realised it was filled with things Mia had never been open about it in our relationship, which seemed like misrepresentations of me with some outright lies I found. However, due to my really poor memory because of my conditions, I found it hard to be sure what the truth was (in our relationship I always deferred to Mia's memory).

For months I questioned if I was an abuser and went to intensive relationship therapy, read books on personality disorders and abuse, called abuse hotlines, wrote long checklists of my behaviours and compared them to diagnostic criteria, asked for honest feedback on forums and told everyone close to me that I might have abused the person I loved. Everyone just seemed sad that I would take this accusation to heart when they heard the story. Eventually I started to remember all the harmful things my ex had said or done toward the end of our relationship and that it really was a two-way street, though nothing for either of us to be remotely proud of.

But 8 months later I still can't get rid of the shame of the character attacks, misgendering as a man and criminal allegation Mia made in public while abruptly cutting me off without discussion. I also can't get rid of the shame of participating in such a harmful relationship with the person I loved most, who I always tried to cherish. I've stopped hoping for the future, feeling deserving of love or caring for my health anymore. I've stopped trusting my close friends and have begun to push them away. I feel that the people close to me will abandon me one way or another, either by quietly pulling away or by some kind of conflict. I can't hold down a job or even participate in my part-time vocational course right now because I feel so hopeless, unmotivated and afraid of human beings.

I just want to be loved. I want to belong. But I don't think there is a seat for me at any table.

How do I convince myself to stay in a world in which I don't fit in and have so many griefs that weigh down on me?