Hi Fairy,
I want to wish you and your DN and to say how much I admire you for starting this discussion, I hope both of you get help and support, I am not sure if practically I can offer assistance, but I will try to share my story and perspective, without hijacking your thread.
I was adopted by family and it was complicated. My parents died when I was a baby, initially I lived with Grandparents, but DGM died was I was 3. DGF struggled for a while, then I was adopted by an Aunt and a uncle aged 5. Aunt and uncle were mid 40's with no children of their own, and it was thought to be a perfect solution.
Aunt/uncle had not had counselling re infertility (this was the70's), and expected me to be a PFB. I was a strong willed 5yo who had been brought up by other adults and didn't mould easily. I wasn't the child they so clearly wanted, and although in believe they loved me I never felt liked.
Due to age, Aunt and Uncles formative years had been during ww2 and rationing. I was never allowed comics, sweets, or frivolous toys because they hadn't had them as children. Birthday money was to be saved or spent on worthwhile things; I was made to buy a dictionary, for example. The year I needed a scientific calculator for school it was my Christmas present. This wasn't about money and in their eyes, it wasn't mean, they actually thought they were being generous by giving me things they had never had, but they were so out of touch with the parents of my peers.
Another complication was that Aunt's DM lived with us and went onto develop dementia when I was a teenager. Aunt had to deal with her DM at the same time as a hormonal teenager, all without support, and I think she had a challenging few years.
Looking back and reflecting, it wasn't great for me, but nor was it great for them, and Yet I believe that their intentions were good. Yes I was the child and should have had more protection, but they needed support too. Support to deal with their feelings and support and practical help to deal with me. I might have been helped by early counselling and support too.
I am pragmatic as an adult and have been lucky to go on to have my own family, but I am very introverted and often tongue tied, I lack confidence and struggle to believe that I am likeable, and yet I gather as a 5 yo I was quite um rumbustuous, so the me I have become is probably not the real me.
I'm sorry this is so long fairy, but I wonder how much support you are getting as a family? I suspect you, you DH and your DN all have different needs.