Struggling today

My sister has always been the type to compete and try to make everyone hate me. No matter how far I move and how much I let her have everyone and everything, she chases me down and tries to get me into this game with her. I think she enjoys hurting me and my kids. She makes everything about her and her kid. Even causing my parents to miss my sons five year old birthday to go to florida with her early even though they go down their for months at a time. My son was so sad. To make a long story short. The day I announced my second pregnancy she also announced she was going to make an appointment the next day to get her iud out. 3 days later it was out and 4 months later she was pregnant with her second as well. I just had my baby and she’s due in a couple months. My family did nothing for me at all. They didn’t help with my reveal or do anything special because it’s my second but it’s her second baby as well and They threw her a reveal party with elaborate decorations and an expensive cake. Now they are throwing her a big baby shower. I feel so unloved and uncared for. Story of my life with them. My kids are six years apart so I had to buy a new car seat and other things etc but it’s not even about the gifts. It’s about the blatant favoritism. All I want to do is finally have the strength to break ties and be free but the childhood abuse makes me afraid of the backlash.