Hello. Aww I am sorry to hear that this is still affecting you so much. How did the rest of life treat you or did it go as you say, like a stick of rock thro your experiences?
I too was unwanted. My mother wanted a boy and got my older sister, then tried again, sure I was a boy, and was bitter that I was a girl. My brother came along 3 years ago. She was horrible and left my father, took us, was horrible to us but loved my sister and brother just not me. She used to shout it in my face etc, awful treatment.
There was no question I was unwanted. My dad even used to say that if he could go back and do his time again, he wouldn't have children. I've been no contact for many year with them all. but low with him recently as he is old and wad the least bad. But he still doesn't want to know.
The way I dealt with it was to get into therapy young and to build back what was lost. I built a relationship with an older couple I used to lodge with and now they ae my family. I also did therapy and got into the old 'design your life' thing, solving my problems, trying to do things I personally thought were cool options, trying to be happy and do what made me happy and fulfilled.
It was only the start. The whole of the rest is what's left. You are not unloveable in any shape or form. Their failures were down to them and you got caught in the cross fire, that's all. The sooner you got out the better, and you are out, and what are you going to make of the rest of your life? That is the only question.