I sympathise OP, I really do. I also had a bit of a dysfunctional childhood. My parents split up when I was five and my dad 'let' my mum take me but fought (and won) to keep my brother with him. Maintenance for me was set at 5p a year (it was in the 1970s).
My mother would then regularly remind me of this throughout my childhood "your dad didn't want you, he only wanted your brother", "basically your dad doesn't really care about you", she would also recount this story to others in front of me (and would continue to tell the story, even if I was in tears).
My brother's and my upbringing were like an edition of Rich House, Poor House. He always had the latest fashions, trainers etc, whereas my clothes always came from the charity shop.
I was overweight in my teens and very early 20s so had absolutely no admirers. My dad would always say "you're such a pretty thing, if only you'd lose the weight." He offered me £500 to lose weight (a heck of a lot in the 90s) and I did. Suddenly, I had a lot of attention and would basically date whoever showed an interest in me.
I met and married my ExH after some serious love bombing from him, but as soon as we had kids the affairs started and he eventually left for the OW.
It was only after six months of therapy that I realised the effect my childhood had on me, I felt worthless and unworthy of love. My therapist really made me see that my sense of self-worth was through the floor.
Then I did some online dating, and I met someone I was very attracted to. But I was very clear from the start that I did not need a man in my life, and I set clear boundaries.
DP and I have now been together for 11 years and have a very equal romantic partnership. He does more than his share around the house, has raised my children together with me, cared for me through Long Covid, regularly sends me random 'I love you' texts and flowers, and basically treats me in a way that makes me feel more loved and cherished than I've ever felt before.
I think the turning point for me was the therapy, and though it may sound corny, learning to love myself.