I was breastfed until I was 2 and I don't remember nursing, nor did I turn out socially "wierd"...at least I don't think!
What I do remember is having a very close, trusting relationship with my mother that I still benefit from as an adult. When I was a teenager, I didn't make half the stupid mistakes that I could have, and I credit my strong relationship with my mother for at least part of that.
It sounds like you have tried to educate your dh, and he is not open to that at this time. In that case, I would let my words be few at this point and allow the proof to be in the baby. Six months is a long time for a person to change his mind, and the breastfeeding relationship does change over time. Hopefully, as he sees your baby grow and thrive on your milk, and how happy and well adjusted your dd is, he will change his tune, or at least stop whining and trust your judgement.
We're here for you.