I honestly want to leave my husband because of his toxic family

I’ve been married to my husband for almost a year now. We’ve been together for almost 9 years. He’s my high school sweetheart. Since his mother has passed (2 years ago) his dad’s side of the family have been verbally and emotionally attacking me (for a year and half now) all because I set boundaries with his sister. She has been manipulating my husband all his life and me for 3 years. She ran back to their family playing victim and painted me something I’m not. At first I was ready for this battle and stand my ground but now I’m so emotionally and mentally drained from this. My husband won’t stick up for me because he’s afraid of his own dad’s family and I just can’t take it anymore defending myself and sometimes my husband. I just want to be happy and drama free and I feel like I’ll never get that being with my husband. I love him to pieces he’s an amazing father and husband (at times we have our moments but nothing crazy or toxic). I just don’t know what to do anymore, I’m thinking about moving back home and going back to college and finish up where I left and go on with my life. I’m sad all the time and I have really bad anxiety now