I married a man I thought I could fix. His family thought I'd gone a long way towards fixing him too. Everyone commended my valiant efforts and nobody thought to mention that the idea of fixing your partner is very, very flawed. I tried everything I could to fix him. He was severely depressed and was disinterested in doing anything to fix himself, which, I understood, was common for people with depression. On more than one occasion I dumped all the alcohol down the drain, engaged in screaming matches, begged and cried for him to try to do something. I secretly dosed him with St John's wort extract. I was down the rabbit hole of codependency, trying to control all the variables and stuck on an emotional rollercoaster as my efforts were shown to be futile, time and again.
I learned, from my time with him that you can't fix people. You can't really hope for them to change, either. That's not to say that people can't change. They certainly can but it has to be their change, their desire to fix themselves and not for anyone else. But.. the safest bet is to take people at face value and then evaluate whether you want them in your life.
I'm no longer interested in trying to fix people. I don't have a career in psychology, and I am thoroughly disenchanted with the notion of being a hero and saving the day by putting the pieces back together of some broken person. That is not my role, and I'm not interested in trying. Fix yourself if you see fit, and take responsibility for it. I nearly became broken trying to fix the cracks in others. No more.