Can someone please help 🙁

I'm a mum of two (daughter aged 2 and son aged 4 months) with my first born I experienced postnatal depression a while after she was born and it resulted in me not wanting to bond with her and not wanting her (I feel horrible about it now thinking back) I eventually got over all that, Ive always struggled with depression and anxiety but when I got pregnant with my son it got a lot worse and I think I found it harder to manage because I was confused why it was happening. Long story short both of my kids were born 9 and 8 weeks early so I was always very protective. My daughter and my son have different dads though my partner now loves my daughter as his own and has helped me bring her up, when I had our son in may and he was in hospital for 3 weeks my depression and anxiety got a lot worse. I didn't want anyone near him didn't want anyone to hold him or touch him, it was easier with my own family because if I didn't want someone to hold him I can just say can you not lift him please but I find it harder with my partners boyfriend. One day we were out with the kids and I was carrying my son (getting out that day was a very big step for me) we ran into my partners cousin (who I knew before we started our relationship) and she put her hands out as if to say let me hold him and I said in a nice way I'm feeling quite anxious being out I don't really want anyone to hold him, long story short she didn't take it well and none of us have spoken, I explained to my partners sister about what happened and she understood why I did it. Now for me it seems like I find it hard to be around my partners family as they're all quite forward and I find it hard to be social with people as it is I feel like my sons umbilical cord is still attached, I feel a sense of anger when someone touches him etc. My partners sister has put pictures on Facebook a few times until I spoke to my boyfriend about it and said she should ask first and she shouldn't really need to put pictures of him up, he has 4 other sisters and 3 brothers and none of them do it, it just bothers me and I feel like it's making it harder for me to stop being so anxious. I don't it any way want to keep my son away from his family I just don't know how to help the way I feel