Disrespected by part of my Husbands Family

Laura • Married to my best friend and I am blessed to be able to be a stay at home Wifey and Mommy to 3 beautiful kids!
Ok.. So my husband and I have been together for 7 years we have 3 children 2 from his previous wife and 1 that my husband has taken care of since he was a year old. For 3 years my husbands biological mother and stepfather loved me and my son and welcomed us with open arms. Then all of a sudden since my husbands sister didn't like me they started treating me badly and would go and spend $400 on Christmas/Birthday stuff for the other kids and get nothing for my son. My husbands ex cheated on him 11 times and is a horrible mother to our other 2 children and his whole family bashed her etc.. Well since they have started treating myself and our other son unfairly my husband asked them of course to stop but they didn't so we have cut all ties with them (there's way more that happened but you get the jist). Well now on purpose they post pictures of his ex to our sons Facebook and it makes him extremely uncomfortable and he deletes them. Yesterday my husbands sister who I thought we were ok posted pictures on Facebook of him and her and tagged me in them! This makes 5 times all together his mothers side of the family has done this. They also go to his ex wife's house and she goes to there's. She uses them as a babysitter basically when it's her week for the kids. My husband has always stuck up for me and asked them to please stop . The only part of his family that treats me part of the family is his real dad and step mom. I'm tired of getting my feelings hurt I've never cheated on my husband He has PTSD and I'm his caregiver I take care of all the children like they are mine but I still get disrespected. Has anyone ever had this issue before? Please help I need some positive vibes my way! 
This is his sister inviting his ex and her boyfriend to her house while at the same time bashes her to me
 And this is the picture I was tagged in.. I mean seriously you've never heard of cropping!