Why do I get treated like this by my family?

Why does my family think I belong in a Mental hospital? I know I messed up in 8th grade(I’m a sophomore now) and cut myself and stuff. But they just…think I’m like insane. =’[ It really hurts to hear your sister pull you off to the side and say “I don’t know what to do with you. You’re going crazy haley. I want you to be okay but I don’t thik you ever will be. You need to go to a hospital and get help because obviously the therapy just isn’t working.I can’t see you until I know you’re okay. It hurts me to see you like this, I know when you smile, they’re fake smiles. I don’t want to see you anymore because it’s hurting me.” How would you feel if your sister said that to you? =’[

I have gotten much better but I broke down recently and did it again. When she saw them she knew what they were and lost it. She started crying and said "Haley Brooke! No...I can't...You can't make me go through this again. I just can't. I can't be around you when I know you're doing that; it hurts me too much. I won't tell dad or anyone, but I'm gone until you're fixed." I said "Steph, I'm like an old car, no matter how many times you fix me, im never going to run right." She just looked at me, hugged me, kissed my forhead and was gone. That's how my easter went today...I lost my sister. ='[

What am I supposed to do…I’m so lost…She tells me to open up to her but I just can’t it’s so hard. =’[