What is the difference between giving up and surrender? Americans are not good at surrender. Not at giving up either. In fact, most of the unfortunate things that have happened to me in my life are a result of not giving up.
Yet, I think that it is the negative image giving up or surrender holds that makes us disinclined to take a different course, to let go of something/someone toxic, or to allow for the peace associated with the simple act of not fighting to replace the tenacious grip we have on some things.
Some years ago, I was assigned to a rural junior and senior high school to do a concurrent student teaching assignment. Half the day in the middle school; the other half with 7th graders. The typical assignment is split them up allowing for part of the day out of school. That part gives you time to work at a job or to take care of youngsters of your own, or to grade homework and do lesson planning for the next school day.
I can't remember why is was that I ended up with the concurrent assignment. What I remember is getting about 4 hours of sleep a night. But that wasn't the bad part. I was assigned two "critic" teachers who simply walked out of their rooms and let me carry on my own. Unfortunately, they were highly critical of my work. Worse, they undermined my work.
When did I know it is bad? How about within the first week. Why didn't I say something to my university contact? Because I don't quit. I put my head down and put my shoulder into it. My university contact was furious that they treated me the way they did. And furious with me that I didn't say something earlier. I would have been taken out and reassigned immediately. Perhaps I wouldn't have waited more than a year to apply for my license. My thought was that if that is the way professionals treat each other, I did not want to teach.
I can't tell you how many times something like this has happened. I don't want to be a quitter. I don't want to be the whiner/loser/victim/lazy one.
But, sometimes we need to let go of things. Sometimes we need to give up the unrealistic expectations - especially about people. Sometimes we need to surrender ourselves to the inexorable marching of time.
In surrender - or in giving up - we gain. Gain self-respect. Gain peace. Gain perspective.

Sorry to hear that your learning to "let go" was so painful; but, it is a lesson well worth the learning. Congratulations on making it through! You got there!