Help needed I'm very desperate

Today , she left a note on her food in the fridge that it is hers and no one  should touch it. As my husband never opens a fridge and she knows it,  it was obviously directly   addressed to me. This whole time she has been moving my food in the fridge the way she wanted and I never said anything. I have not touched any of her belongings ever and she dares to leave a note like this . I told my husband and got attaced me, he said I should ignore her and he yelled so loud saying : she is my sister  and I love her no matter what, and she heard it . I'm so tired of it . I'm only child and my parents always pampered me, now I have to deal with this . All I wanted her to be clean and wash after she eats . Every time I want to cook I have to clean after her first before I can start cooking and after I'm done cooking . This is so tiring . The other day  me and my husband had friend come over , and my sister in law saw him and said hi Mike , and my husband asked her why do you say hi only to Mike is he the only person in the room and she said yes he is the only one I see . Sorry for such a long post but I need your advise , I love my husband , and I never hated his family and only thing I asked her was to be clean , now I have to accept eveythung she does and deal with it because I never win 😔😭😭😭😭