Will i be held fr abetting to suicide if i break up.

I would like some advice. i have been in a physically, emotionally, mentally and sexually abusive relationship for 15 years. I have always kept quiet and never spoken to any one about it including my family. but now i cannot take it anymore. i am planning to leave him but i am also terrified of him. i am terrified of the harm he can cause to me or my family and friends. moreover, i am terrified that he will commit suicide as he has always claimed he would do that if i ever left him (occasionally also telling me jokingly that he would throw acid on me). i have started making plans and am seeking opportunities to go abroad away from all this but i have not told him any of it, as i know he might make it difficult for me to go. although he has always wanted to marry i have been clear from the start that i did not believe in the institution although i was fine with the idea of living together. i cannot take this anymore and am terrified everyday and have decided to call it off. bt i am afraid of being held up fr abetting to suicide. pls advice.