Hi Hlauren and nice to meet you. I do understand the feeling of being trapped with an abuser. It is really bad when the abuser is your own family living in your own house. My sister used to abuse me when growing up and we used to share a room so there was no escape.
I was saved when she went to a university out of town so then the abuse was reduced to when she came back home.
I also had experience with therapists who didn’t believe me or thought it was my fault for being weak and not standing up to her. I changed the therapist in those situations.
If there is any family member who could help you by taking you in until you can live on your own, that will be the best solution. You should only consider going somewhere where people believe you and they do not abuse you further.