There's nothing profound I can tell you that you haven't heard from people far more experienced than I, but maybe I can offer this...
(Forgive me for the roundabout lead up. I don't want to get bogged down with details, but at the same time I feel like there is a certain level of information in order to convey things properly.)
My mother was a romantic. Also, despite being extremely intelligence, she was extraordinarily naive and innocent. She literally viewed the world as if it was a Disney movie. (Complete with strange ideas about what animals do when we aren't around. I once spent the better part of an hour trying to explain that my cat wasn't going to visit a girlfriend when he went outside in a Lady and the Tramp type scenario.) When she met my dad, it was like a storybook romance to her. Things proceeded how those stories usually do, complete with tragedies overcome along the way. Deaths of friends and family, my dad being sent to Vietnam while my older brother was a newborn. But throughout it all, that sense of old fashioned boy meets girl romance maintained. I've been told a million wonderfully happy stories as well as of countless hardships. To skip a few decades in the name of brevity, one day my dad informs her he is having and affair and wants a divorce. She... did not see that coming. At all. Like... not even the tiniest little bit. Her faith in him and in the story had been absolute. I led up to this in such a manner to show that, while few divorces are pleasant, because of who my mom was as a person, this was very much an extreme.
She made her first attempt to take her own life shortly after. And not a cry for help attempt, she genuinely believed she was doing the right thing and that if that was happening it was because of her and that everyone else was better off without her. Suffice to say, I and my brothers and the countless people who viewed her as all but a living saint did not see it that way. And as the use of the word first implies, the attempts continued. Thankfully it turned out she wasn't very good at committing suicide, and I do not mean that in a glib sense in the slightest.
She spent the remaining years of her life in a state very reminiscent of the one you described here.
On the first line... She thought she was too old to start dating or make new friends, and didn't really have a desire to try. (In her mind, her marriage was until death, even if by any even religious standard because of my dad's actions she was no longer bound by marriage vows.) Beyond that, she didn't believe she had anything in the future to look forward to at all. (Her one big thing in that regard was she worried about me since I was still dependent on her, but that's not exactly the same as hope for the future.)
On the second line... She said a number of times that this was not how she wanted to live, nor ever remotely envisioned spending the rest of her life. Her life was certainly not on her own terms.
And the third line... self-acceptance... well, she was always still convinced that it was all her fault, and she never really did make peace with that.
Yet... despite all of that, she kept going. She never did reconcile those three issues, but yet she still managed to live and actually begin to live fairly happily, more and more as time passed. Not in the way she wanted to be, not with the person she wanted to be happy with, and not at peace with herself. And despite it all, when she did pass away, while she accepted she was dying she no longer wanted to die. It confused her after everything else that came before that she could want to not just survive, but truly live.
Maybe those three things are important. But at the same time, maybe they aren't a prerequisite to truly living.
I don't know what all of this means in the context of what you are going through, I don't even begin to assume that it helps in the slightest... I don't know anything basically except that I know I don't anything. But I couldn't help but think of all of this while reading your post, and I felt that if there is even a tiny fraction of a chance this does mean anything, it was worth saying.
