Malice, At Last

On my struggles with too much empathy and letting people take advantage of me because I've always wanted to believe in the best of humanity. Stretched to my breaking point, I think we can see that's no longer true. But i still do it, because it's my instinct and my desperate need to help. I'm stuck. Parts of me want to only be violent with myself, because that's how it's always been, and other parts... not so much. It's worse because I've always had to bottle everything up, and thus have decimated my arms over the years. But now... And how do you write out your violent feelings when you can't stop breaking your pencil or afraid of breaking your keyboard? Any and all helpful advice would be appreciated.