What worked for me was viewing it as "taking my power back".
I decided that no one would/could dictate how I feel unless I chose it.

I chose to become responsible for how I feel and not allow those who failed me in my formative years to have that power. They would no longer have the power to lower my self esteem, cause me to be depressed or less than in any way. That was over. I was done with that.

Instead, I found deep compassion for what I had gone thru, rather than feel sorry for myself (and I was a master at that) or hate others who had no ability to be better.

I eventually found compassion for those who so-called raised me, and came to realize that they were mentally ill themselves.

Please know that I am simply describing what worked for me. I still have mental health issues as I am bipolar, but I no longer blame anyone else for my depression or mental health challenges. In other words, I am far from perfect, but the hatred is gone from my heart, and that is very freeing for me.