If it wasn't for baby age and sex you could be my sister. 
So for me, everyone wrongly assumed and pushed PND. I actually had post natal anxiety and still do. I also had or have ptsd caused by many years of losses and infertility not being processed by me.
The trigger for me was my best friend in the world visiting, bringing three children, who I adore, and giving DD a cold. To this day, nine months on, it makes my blood run cold. It started a cycle of fear, anxiety and hurt that I don't think I have or will ever get over.
I wanted to be that mum, relaxed, happy, content, but I couldn't. I was absolutely terrified something or someone would harm my baby. She was the only baby who had survived and the fear of something happening to her still grips me.
Nobody has looked after her, very few hold her, I just want my baby, safe with me. I am getting better, and to be honest I'm only really expressing it for the first time here, but it was very hard. Instead of feeling loved and protected by family, I felt suffocated and pressured. I felt Judged and isolated. Yet I was pushing them away. DD only got sick when others came near her, I didn't give her anything.
I'm sorry if I'm rambling but this strikes home with me. I love my sister but it's just to much for me just now. I never nested during pregnancy or even really believed the pregnancy was happening. I think this is my nesting period now.
Just keep doing what you are doing OP. It will get easier, but I wouldn't push a diagnosis or her at the moment. Early days.