I need advice from people in my situation.

As a hikikomori, I have no friends and I’m terrified to even step into a grocery store for fear someone will recognize me. Naturally my cat is a very big part of my life, I would consider her to be my only friend. The problem is I live with my family, who my therapist claims is a big reason for why I turned out the way I did. My siblings kick my cat and shove her in a box when they upset them. My dad hits my cat when she scratches and stops feeding her. My innocent friend isn’t going to learn anything, and she doesn’t deserve it. It seems like my girl is being reduced to a stuffed animal for people to play with, she has no autonomy of her own. So I’m considering taking my cat into the woods and shooting her.