When I first fell ill, I began to think of myself as consisting of two parts: my body, which was sick and causing me problems, and my mind, which was healthy and longed to get rid of the illness.
Now, I tend to think of myself as a whole. My mind and my body are two sides of the same coin. They are equally responsible for my well-being or lack thereof.
You say that suicide is self-defence.
A more accurate description, in my case, is that I am killing myself to live.