In-laws not respecting you as a mother and impacting on your mental health

[Ineedadvise]

I gave birth to my beautiful baby girl in February I was so excited to be a mum. But the minute my daughter was born my partners family turned on me. My partner mum pushed me to take my baby over to her house so the rest of the family could meet her
(Please keep in mind I had a tragic traumatic labour where I had seizures, put on the sepsis pathway, was induced due to my SPD and diabetes and my daughter torn my muscle in my pelvis)
me and partner asked everyone to come to our house. We moved in to stay at my mother’s house so I had support to help me as I was very unwell during my pregnancy. But my partner sister refused to come to us only to them we eventually met up on mutual ground after the sister and mother slated me as a mother and slated my mam who done nothing to them but support my little family.
i had an argument with the sister due to wanting to come and take my daughter out without me who doesn’t even come and see her and doesn’t even know my daughter. I had to watch the sister younger child hit my 4 week old daughter but non of the family tried to stop it as they were busy getting a photo of all three cousin. I said nothing bad to the sister but it wouldn’t be happening but sins then every person in the family has turned against me are rude every time I’m around and don’t hand my daughter too me if she screams I have to watch it and it hurts so much as she does not know them and can sense I’m anxious. I was diagnosed with postnatal anxiety and depression and find hard to sleep as I have to be with my daughter and the thought of her being away mentally I struggle with I’m having ongoing tests as the seizures I’m having are linked to anxiety.

my mother and step farther had my partner mother and farther over to talk about coming over and trying build the relationship back with me the farther agreed even though he done nothing wrong but the mother will not allow it and has to see opal in her own home and will not respect we do not want my partner sister in our life and is not invited to the christening

am I in the wrong for any of this and is anyone experienced the same as I feel like the worst person and the worst mum

Pack a few bags. Go and recover from the birth with your family. Your dp /dh can manage the shit show his family have created..
Cancel the christening for now. It really ain't worth the stress right now.. Tell him you wil bring the baby home when the war is over....

This sounds similar to the situation I had with my DHs family. I tolerated it, it never got better, they pushed and pushed until we almost snapped and these days have very little to do with them.
Step back now when you have the chance, don’t tolerate this shit because it will only get worse. Tell your mum/step father to not let them in again. If they demand you visit them, well, you aren’t going because you are unwell, end of. Don’t bend and fold for arseholes. They aren’t worth it. If they don’t respect you after everything you have been through, then leave them to stew.

Had the same with my in laws and our relationship has never been the same. They stomped all over my boundaries, made snide comments about my breastfeeding, would push to take my dd out for walks without me, would try to separate her from me. It was truly awful. It 100% impacted my post partum experience. We had a huge argument and i have minimal contact with them since, the relationship with dds is maintained by partner. My mil is completely manipulative so any conversation with her went in one ear and out the other! Do whatever you have to do to make yourself and your family happy