I am sorry that you are in that situation and I can definitely relate to what you wrote from my own personal experience.

That your parents try to guilt and shame you constantly is just awful. It is especially horrible since they are attacking something that you are very sensitive about. That's really heartbreaking.

There is medical research that seems to indicate that not only is emotional abuse [such as body shaming] psychologically damaging but also that it causes damage to the brain by exposing the brain to corticosteroid hormones in excess.

The link seems to be that corticosteroids in excess damage both the brain's white and grey brain matter.

Sadly preliminary medical research is also tending to show that stress from adverse childhood experiences prevents a child's brain from developing properly [ACE Study].

Children who had certain types of adverse childhood experiences showed maldevelopment of regions of the brain as well as dysfunction in key processes such as regional cerebral blood flow and energy utilization [glucose metabolism].

Self-defense is one of nature's oldest laws and sometimes we have to go to great lengths to prevent further brain damage from abuse.

I had to set very hard boundaries with one of my abusive parents and somewhat softer boundaries with another for the sake of my mental health. Some people have to cut ties.

Just as we would not allow a loved one to beat us physically, so I believe we cannot allow a loved one to harm our brains.

My father, I believe had an undiagnosed serious mental illness. I could feel empathy for him in the sense that I think his illness profoundly affected his behavior, but at the same time, I had to protect myself too.

Sadly, some loss are necessary losses, I fear.

My heart goes out to you.